AW INVESTIGATION OF THE ELECTRIC MOMENTS OF SCME COMPOUNDS OF FLUORINE By R ic h a rd D. P r u e t t A THESIS S ubm itted to th e S ch o o l o f G rad u ate S tu d ie s o f M ichigan S t a t e C o lle g e o f A g r ic u ltu r e and A p p lied S c ien ce i n p a r t i a l f u l f i l l m e n t o f th e re q u ire m e n ts f o r th e d e g re e o f DOCTOR OF PHILOSOPHY D epartm ent o f C h e m istry 195h ProQuest Number: 10008411 All rights reserved INFO RM ATIO N TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest. ProQuest 10008411 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 - 1346 c ACKNOWLEDGMENT The a u th o r w ish e s to e x p re s s h i s s in c e r e a p p r e c i a t i o n t o P r o f e s s o r M. T . R ogers f o r h i s g u id an ce and a s s i s t a n c e th ro u g h o u t th e c o u rs e o f t h i s w o rk , t o D r. J . L . S p e ira and D r. H. B . Thompson f o r t h e i r h e lp i n th e c o n s t r u c t io n o f e q u ip m e n t, and t o th e Atomic E nergy Commission f o r a g ra n t s u b s id is in g t h i s re s e a rc h . -5 H H B S f* * «W ■a VITA R ic h a rd D. P r u e t t C a n d id a te f o r th e d e g re e o f D o cto r o f P h ilo s o p h y D is s e rta tio n ; An I n v e s t i g a t i o n o f th e E l e c t r i c Moments o f Some Compounds o f F lu o r in e O u tlin e o f S tu d ie s ; M ajor F i e l d — P h y s ic a l C h e m istry M inor F i e l d — P h y s ic s and M ath em atics B io g r a p h ic a l D a ta: B o rn , December 2 0 , 1 9 2 8 , M a tto o n , I l l i n o i s U n d e rg ra d u a te S t u d i e s , I n d ia n a U n i v e r s i ty , B lo o m in g to n , I n d i a n a , 19^6-1950 G rad u ate S t u d i e s , M ich ig an S ta te C o lle g e , E a s t L a n s in g , M ic h ig a n , 195>0-195li TABLE OF CONTENTS Page I . INTRODUCTION........................................................................................................ I I . HISTORICAL REVIEW................................. 1 3 I n t e r h a l o g e n s ........................................ ........................................... ................................................................................. F lu o r o c a r b o n s P h y s i c a l P r o p e r t i e s .............................................................. M o le c u la r P r o p e r t i e s .................................................... .................... 3 U U 8 I I I . THEORETICAL BACKGROUND................................................................................. 12 IV . APPARATUS AND METHOD...................................................................................... 19 Review o f M ethods ............................................................. ......................................................... H e te ro d y n e -B e a t A p p a ra tu s G e n e ra l P r i n c i p l e s ................................. V a r ia b le O s c i l l a t o r ........................................................................... ........... C ry s ta l O s c i l la to r P r e c i s io n C o n d e n se r................................................... C a l i b r a t i o n o f P r e c i s io n C o n d e n se r................. R e fe re n c e F re q u e n c y ................................................................... D i e l e c t r i c C o n s ta n t C e l l s .................................................................... C e ll 1 ........................................................................................................ C e ll I I ...................................................................................................... G as-H andling S y ste m s............. Vacuum L in e 1 ........................................................................................ Vacuum L in e I I ...................................................................................... T em p eratu re M easurem ent and C o n t r o l ............................................. T e m p e ra tu re -C o n tro lle d B ath I ................ T e m p e ra tu re -C o n tro lle d B a th I I .............................................. The T h e rm o re g u la to r.......................................................................... T em p eratu re M easurem ent.................................................................. M a te ri s i s .................... H alogen F l u o r i d e s ............................................................................... F lu o ro c a rb o n D e r i v a t i v e s ............................................................... Gases Used f o r C e ll C a l i b r a t i o n .................................... P r o c e d u r e ........................................................................................................ C e ll Ca l i b r a t i o n ................................... C e ll I .......................................................................... C e ll I I ............................................................................................... D i e l e c t r i c C o n sta n t M e asu rem en ts............................................. T re a tm e n t o f D a ta ............................. C a l i b r a t i o n o f C e l l s ........................................................................ 19 20 20 2b 2b 28 30 32 3b 3b 36 38 38 38 bZ b2 b2 U5 bl k& It 8 b9 U9 50 50 50 51 51 52 52 TABLE OF CONTENTS - C ontinued .................................................................................. C e ll I C e ll I I .................................................... ............................................. C a lc u la t io n o f D ip o le Moment......................................................... V. RESULTS..................................................................................................... Page 53 55 56 57 H alo g en F l u o r i d e s .................................................... ................................... 57 ............................................................. 57 Brom ine P e n t a f l u o r id e 57 D a ta ........................................... . .............. .................. ................................... .. 58 D ip o le Moment C h lo rin e T r i f l u o r i d e ............................................. 76 D a ta ........................................................................................................ 76 76 D ip o le Moment............................................................................ I o d in e P e n t a f l u o r i d e .................... 79 D a ta ..................................................................... 79 ...................................................................... 83 D ip o le Moment — 83 Brom ine T r i f l u o r i d e ........................ D a ta ....................................................................................................... 83 83 D ip o le Moment.......................................... F lu o ro c a rb o n D e r i v a t i v e s ........................................................................ 86 1 , 1 , 1 , 2 , 2 , 3 , 3-H e p ta flu o ro p ro p a n e ................... 86 D a ta ...........................................................................*........................... 86 D ip o le Moment............................... 86 ........................................... 86 P e r f lu o r o ta tr a m e th y le n e O x id e D a ta ........................................................................................................ 86 86 D ip o le Moment...................................... P e r f l u o r o e t b y l E th e r ..................................................................... 93 93 D a ta ............... D ip o le Moment................................................................................... 93 C h l o r o t r i f lu o r o a th y le n e ................................... 93 D a ta ............................................. 93 D ip o le Moment.................................................................................... 93 D is c u s s io n o f E r r o r s .................................................................................... 100 H alogen F l u o r i d e s .............................................................. 100 C e ll C a l i b r a t i o n ............................... 102 D i e l e c t r i c C o n sta n t M easu rem en ts........................................... 102 M olar P o l a r i s a t i o n ............... 103 D ip o le Moment...................................................................................... 10ii F lu o ro c a rb o n D e r i v a t i v e s ................. 105 V I. DISCUSSION OF RESULTS........................................................................................ 108 H alogen F l u o r i d e s ............................... C h lo rin e T r i f l u o r i d e .......................................... Brom ine T r i f l u o r i d e .......................... 108 108 108 TABLE OF CONTENTS - Continued Page Bromine P e n t a f l u o r i d e ........................................................................... 109 I o d in e P e n t a f l u o r i d e ..............................................................................110 .................................................................... I l l F lu o ro c a rb o n D e r iv a t iv e s 1 , 1 , 1 ,2 ,2 ,3 , 3 - H e p ta flu o ro p r o p a n e ....................... ....................... I l l P e r f lu o r o te tr a m e th y le n e Oxide and P e r f l u o r o e t h y l E th e r 112 C h l o r o t r i f l u o r o e t h y l e n e .......................................................................113 V I I . 3UMHARI................................. HU LITERATURE CITED 116 LIST OF TABLES T able I II III Page S t r u c t u r a l D ata f o r Some o f th© I n te r h a lo g e n C om pounds*.,. 5 C om parison o f Some P h y s ic a l P r o p e r t ie s o f F lu o ro c a rb o n s and H ydrocarbons ..................................................... 7 M o le c u la r C o n s ta n ts o f Some F lu o r o c a r b o n s .................................... 10 D ip o le Moments o f Some F lu o r o c a r b o n s .................. 11 V D i e l e c t r i c C o n s ta n ts o f Ammonia Vapor a t S e v e ra l T e m p e ra tu re s .......................................................................... 5U IV VI D i e l e c t r i c C o n s ta n t D a ta F o r Bromine P e n t a f l u o r i d e ................ 59 D a ta f o r th e C a l i b r a t i o n o f th e G en eral R adio P r e c i s i o n C o n d e n s e r....................................................... 65 C a l i b r a t i o n D a ta f o r th e H e lic o id Gage ............................... 67 ........................... 69 X V a lu e s o f A C f o r C arbon D ioxide from D a ta i n T a b le I X . . . 71 V II V III IX XI C a l i b r a t i o n D ata f o r D i e l e c t r i c C e ll I I V alu es o f A C f o r Bromine P e n ta f lu o r id e from D ata i n T a b le V I ............................................................................................................... 73 C a lc u la t io n s o f M olar P o l a r i z a t i o n s f o r Bromine P e n ta ­ f l u o r i d e ........................................ lh D i e l e c t r i c C o n s ta n t D a ta f o r C h lo rin e T r i f l u o r i d e .................. 77 XIV M olar P o l a r i z a t i o n C a lc u la tio n s f o r C h lo rin e T r i f l u o r i d e . . 76 XV D ip o le Moment o f C h lo rin e T r i f l u o r i d e C a lc u la te d U sin g th e M olar R e f r a c t i o n .............................................. 79 X II X III XVI D i e l e c t r i c C o n s ta n t D a ta f o r Io d in e P e n t a f l u o r i d e ................... 80 XVH D ip o le Moment C a lc u la tio n s f o r Io d in e P e n ta f lu o r id e by th e R e f r a c t i v i t y M ethod.................... 82 X V III D i e l e c t r i c C o n s ta n t D ata f o r Bromine T r i f l u o r i d e ..................... 81i XIX D ip o le Moment C a lc u la tio n s f o r Bromine T r i f l u o r i d e ................ 85 LIST OF TABLES - Continued XX Page D i e l e c t r i c C o n s ta n t D ata f o r 1 , 1 , 1 , 2 , 2 ,3 ,3 - H e p ta f lu o r o p r o p a n e ................................................................................................................. 87 M olar P o l a r i z a t i o n C a lc u la t io n s f o r 1 , 1 , 1 , 2 , 2 , 3 , 3 -H e p ta f lu o r o p r o p a n e .................................................................................................... 89 XXII D i e l e c t r i c C o n s ta n t D a ta f o r P e r f lu o r o te tr a m e tb y le n e Oxide 90 X X III M olar P o l a r i z a t i o n C a lc u la t io n s f o r P e r f lu o r o te tr a n e tlT y lene O x id e ............................................................................................................ 92 XXIV D i e l e c t r i c C o n s ta n t D ata f o r P e r f l u o r o e t h y l E t h e r .................. 9^ XXV M olar P o l a r i z a t i o n C a lc u la tio n s f o r P e r f l u o r o e t h y l E t h e r . . 96 XXVI D i e l e c t r i c C o n s ta n t D a ta f o r C h l o r o t r i f l u o r o s t h y l e n e 97 XXVII M olar P o l a r i z a t i o n C a lc u la tio n s f o r C h l o r o t r i f l u o r o e t h y l e n e ................................................. 99 XXI XXVUI D ip o le Moments and M olar P o l a r i z a t i o n s D eterm ined i n T h is I n v e s t i g a t i o n ...................................................................................................... 107 LIST OF FIGURES are Page 1 . B lock diagram i l l u s t r a t i n g th e p r i n c i p l e o f th e h e te ro d y n e b e a t a p p a r a tu s ........................... 21 2 . C i r c u i t o f th e h e te r o d y n e - b e a t a p p a r a t u s ......................................... 25 3 . C i r c u i t o f th e v o l t a g e - r e g u l a t e d power s u p p ly .............................. 27 l+. P rim a ry s ta n d a r d c a p a c i t o r u se d f o r c a l i b r a t i n g G en eral R adio p r e c i s i o n c o n d en se r ...................................... 31 5 . C a l i b r a t i o n c u rv e f o r s ta n d a r d p r e c i s i o n c o n d e n s e r .................... 33 6 . C e l l I , d i e l e c t r i c c o n s ta n t c e l l f o r n o n - c o r r o s iv e g a s e s . . . 35 ............................ 37 8 . Gas h a n d lin g system f o r n o n -c o rro s iv e g a se s (Vacuum L in e I ) 39 9 . Vacuum system f o r h a n d lin g h a lo g e n f l u o r i d e s (Vacuum Lin© I I ) ............................................................................................... 1+0 7 . S e c tio n th ro u g h th e c y l i n d r i c a l C e ll I I 1 0 . T e m p e ra tu re -r e g u la te d b a th (B ath I ) f o r g la s s - e n c lo s e d d i ­ e l e c t r i c c e l l ( C e l l I ) ............... 1+3 1 1 . T e m p e ra tu re - re g u la te d B a th I I f o r C e l l I I . ..................................... 1+1+ 12 . T h e rm is to r th e rm o r e g u la to r c i r c u i t .................................... 1+6 1 3 . T y p ic a l c a l i b r a t i o n c u rv e f o r th e H e lic o id p r e s s u r e g a g e . . . 68 11+. T y p ic a l p l o t o f c e l l c a l i b r a t i o n d a t a ................................................ 70 1 5 . T y p ic a l p l o t o f c a p a c ita n c e v e rs u s p r e s s u r e f o r brom ine p e n ta f lu o r i d e a t 1 1 5 .8° C ............................................... 72 1 6 . M o lar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r brom ine p e n t a f l u o r i d e ................................................ 75 1 7 . M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r c h lo r in e t r i f l u o r i d e .................................................. 78 1 8 . M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r 1 , 1 , 1 , 2 , 2 ,3 , 3- h e p ta f lu o r o p r o p a n e .......... 89 LIST OF FIGURES - Continued Page 1 9 . M o lar p o l a r i z a t i o n v e rs u s t h e r e c i p r o c a l o f th e a b s o lu te te m p e r a tu re f o r p e r f lu o r o te tr a w e th y le n e o x i d e ......................... 92 2 0 . M o lar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r p e r f l u o r o e t h y l e t h e r .............................................. 96 2 1 . M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r c h l o r o t r i f l u o r o e t h y l e n e ....................................... 99 2 2 . P ro b a b le e r r o r as a f u n c tio n o f c a p a c ita n c e in c re m e n t, A C f o r a s i n g l e o b s e r v a tio n u s in g C e ll I I ...................................101 23- P ro b a b le e r r o r as a f u n c tio n o f c a p a c ita n c e in c r e m e n t, /V C f o r a s i n g l e o b s e r v a tio n u s in g C e ll 1 .....................................101 LIST OF PLATES F o llo w in g Page P la te I II P rim a ry s ta n d a r d c a p a c i t o r u se d f o r c a l i b r a t i n g P r e c i s io n C ondenser ..........................*.................. 31 Components o f d i e l e c t r i c C e ll I I 37 1 X. INTRODUCTION E l e c t r i c d ip o le moment d a ta p r o v id e im p o rta n t in f o r m a tio n i n s t r u c t u r a l o h e m is tr y . Combined w ith o t h e r s t r u c t u r a l d a t a , d ip o le moments p r o v id e in f o r m a tio n c o n c e rn in g th e sh ap e o f m o le c u le s and th e bond a n g le s , a s w e ll a s d e t a i l s o f th e e l e c t r o n i c s t r u c t u r e s o f m ole­ c u le s su c h a s i o n i c - c o v a l e n t bond re s o n a n c e and re so n a n c e among v a le n c e -b o n d s t r u c t u r e s . B ecause o f t h e h ig h r e a c t i v i t y and g e n e r a l n a tu r e o f th e h a lo g e n f l u o r i d e s , v e ry l i t t l e work had b e en done w ith them b e fo r e 19U6. The d ip o le moments o f o n ly two o f th e s e com pounds, c h lo r i n e m o nogluorid e and c h lo r i n e t r i f l u o r i d e , had b een m easured d i r e c t l y a t m icrowave f r e q u e n c i e s , and none had b een m easured a t r a d io f r e q u e n c i e s . As a r e s u l t o f t h e p r e s e n t i n t e r e s t i n fT u o rin e c h e m is tr y , b o th i n in d u s t r y and i n th e governm ent, many h a lo g e n f l u o r i d e s , f lu o r o c a r b o n s , and f lu o r o c a rb o n d e r i v a t i v e s a re now a v a i la b l e f o r s tu d y . The d ip o le moments o f s e v e r a l o f th e s e compounds were m easured i n th e v a p o r p h a s e . Equipm ent was b u i l t w ith which t o c a r r y o u t th e s e m ea su re m e n ts, b o th on compounds t h a t p o s s e s s s u f f i c i e n t v a p o r p r e s s u r e a t room te m p e r a tu r e , and on compounds t h a t b o i l c o n s id e r a b ly above room te m p e r a tu re . S p e c ia l m ethods f o r h a n d lin g and p u r if y in g th e h a lo g e n f l u o r i d e s have been d e­ v e lo p e d and a d d i t i o n a l equipm ent c o n s tr u c te d w ith which t h e i r d ip o le moments c o u ld be d e te rm in e d . 2 The d a t a th u s o b ta in e d shed f u r t h e r l i g h t on t h e m o le c u la r s t r u c ­ t u r e s o f th e h a lo g e n f l u o r i d e s and f lu o r o c a r b o n d e r i v a t i v e s s t u d i e d in th is in v e s tig a tio n . 3 II. HISTORICAL REVIEW I n t e r h a l o gens An e x c e lle n t; summary o f th e c h e m ic a l and p h y s ic a l p r o p e r t i e s o f t h e h a lo g e n f l u o r i d e s h a s b een p r e s e n te d by Thompson i l ) . B ooth and P in k s to n h a r e w r i t t e n a c h a p te r on th e h a lo g e n f l u o r i d e s i n th e book F lu o r in e C h e m istry ^2) , and s e v e r a l re v ie w a r t i c l e s on t h e c h e m is try and p h y s i c a l p r o p e r t i e s o f th e s e compounds have a p p ea re d ( 3 ,ii,S ) . R e l a t i v e l y few d i r e c t m easurem ents o f th e e l e c t r i c moments o f th e i n te r h a l o g e n com pounds, e s p e c i a l l y th e h a lo g e n f l u o r i d e s , have b een re p o rte d . T h is i s due t o t h e i r h ig h r e a c t i v i t y , d i f f i c u l t i e s i n hand­ l i n g and p u r i f i c a t i o n , and l a c k o f a v a i l a b i l i t y . The f i r s t d ip o le moment o f an i n te r h a lo g e n compound was o b ta in e d by Townes (6 ) who r e p o r t e d a moment o f 0 ,6 5 D f o r io d in e m o n o c h le rid e from m icrow ave s t u d i e s . G i l b e r t and R o b e rts C7) o b ta in e d a moment o f 0 ,8 8 1 D f o r c h l o r i n e m o n o flu o rid e , th e f i r s t h a lo g e n f l u o r i d e t o be m e a su re d . T h is r e s u l t was o b ta in e d from m icrow ave d a t a , as was th e moment o f 1 ,2 9 D f o r brom ine m o n o flu o rid e r e p o r te d b y S a i t h , T id w e ll and W illia m s id ) . S heka ^9) r e p o r t e d th e d ip o le moment o f io d in e mono- brom ide t o be 1 ,2 1 D from d i e l e c t r i c c o n s ta n t and d e n s i t y d a ta o f s o l u t i o n s o f io d in e raonobrood.de i n b ro m in e . A v a lu e o f 0 ,6 D f o r th e moment o f brom ine m o n o ch lo rid e was e s tim a te d by F r o h lic h and J o s t (1 0 ) from d i e l e c t r i c c o n s t a n t m easurem ents i n th e l i q u i d s t a t e a t d i f f e r e n t Ai te m p e r a tu r 0 3 . C h lo rin e t r i f l u o r i d e , a c c o rd in g t o Hagnuaon ( 1 1 ) , h a s a moment o f 0.55U D a t m icrow ave f re q u e n c ie s * The s t r u c t u r e s o f th e in te r h a l o g e n compounds have b e en s t u d i e d bye l e c t r o n d i f f r a c t i o n , i n f r a r e d and Raman s p e c tr o s c o p y , and c r y s t a l s t r u c t u r e m e th o d s. The r e s u l t s o f some o f th e s e s t u d i e s a re sum m arised i n T a b le I . F lu o ro c arbons Betw een 1900 and 1925 th e f o u n d a tio n s o f m odern o rg a n ic f l u o r i n e c h e m is tr y w ere l a i d by th e B e lg ia n c h e m is t S w a rt* . He d e v is e d g e n e r a l m eth o d s f o r th e p r e p a r a t i o n o f f l u o r i n e com pounds, and i t was h i s work w iiich r e n d e re d p o s s i b l e , a b o u t 1930, t h e com m ercial a p p l i c a t i o n o f a l i p h a t i c p o ly flu o ro h a lo c o m p o u n d s a s r e f r i g e r a n t s . D u rin g t h e p a s t tw e n ty y e a r s B ig elo w ( 2 , l i i ) , Cady and Simons (2 ) d ev elo p ed m ethods f o r t h e c o n t r o l l e d i n t e r a c t i o n o f f l u o r i n e w ith o rg a n ic compounds, r e s u l t i n g i n t h e s y n t h e s i s o f a l a r g e number o f members o f a new c l a s s o f com pounds, th e flu o ro c a rb o n s . P h y s ic a l p r o p e r t i e s * F lu o ro c a rb o n s h a v in g m o le c u la r w e ig h ts l e s s th a n p e r f lu o r o b u ta n e have h ig h e r b o i l i n g p o i n t s th a n h y d ro c a rb o n s w ith th e same c a rb o n s t r u c t u r e ; f o r th o s e w ith h ig h e r m o le c u la r w e ig h ts th e re v e rs e i s tr u e (2 ) . F lu o ro c a rb o n s a re much more v o l a t i l e th a n h y d ro ­ c a rb o n s o f t h e same m o le c u la r w e ig h t; th u s p e rflu o ro m e th a n e w ith m ole­ c u l a r w eig h t 88 b o i l s a t -1 2 8 °C , w h ile h e x a n e , m o le c u la r w e ig h t 8 6 , b o i l s a t 69°C . F lu o ro c a rb o n s b o i l o n ly s l i g h t l y h ig h e r th a n th e n o b le g a se s TABLE I STRUCTURAL DATA FOR SOME OF THE INTERHALOGEN COMPOUNDS Compound C1F D ip o le Moment Bond D is ta n c e 0 .8 8 D 1 .6 2 8 A C1F3 7 — a a=1 .6 9 8 R e fe re n c e C o n f ig u r a tio n r ■ t .m L rX _ a tp I' 12 0.55U b -1 .5 9 8 0 - 87° 29* e " u F p la n a r BrF 1 ,2 9 B rF3 ----- —— 1 .7 5 9 r— 8 r 13 1 .7 8 I i* p la n a r ? IC1 0.63' IB r 1 .2 1 BrC l 0 .6 2 .3 0 3 15 ----- __ — 9 10 6 o f s i m i l a r m o le c u la r w e ig h t. T h is f a c t e m p h asises th e low in te n n o le c u - l a r a t t r a c t i v e f o r c e s o f th e f lu o r o c a r b o n s . As i s 3hown i n T a b le 1 1 , a co m p ariso n o f m e ltin g p o i n ts o f s a t u ­ r a t e d f lu o r o c a rb o n s w ith th o s e o f s a t u r a t e d ly d ro c a rb o n s w ith t h e same c a rb o n s k e l e t o n shows t h a t th e f lu o r o c a r b o n s have h ig h e r m e ltin g p o in ts . T a b le I I shows t h a t a f lu o r o c a rb o n h a s a d e n s i t y a b o u t tw ic e t h a t o f t h e p a r e n t h y d ro c a rb o n . The r a t e o f change o f d e n s i ty w ith tem p era ­ t u r e i s a b o u t t h r e e tim e s t h a t f o r h y d ro c a rb o n s . L ike th e d e n s i t y , t h e v i s c o s i t y and te m p e ra tu re c o e f f i c i e n t o f v i s c o s i t y a re a p p re c ia b ly h ig h e r t h a n th o s e f o r h y d ro c a rb o n s . T h e ir s u r f a c e t e n s io n s a re e x tre m e ly lo w , f a r lo w e r th a n th o s e o f t h e c o rre s p o n d in g h y d ro c a rb o n s , and in c lu d e th e lo w e s t v a lu e s r e c o r d e d . T h is i s a n o th e r r e s u l t o f th e low in te r m o le c u la r f o r c e s p r e s e n t . As i n d i c a t e d i n T a b le X I, f lu o ro c a rb o n s have v e ry low r e f r a c t i v e i n d i c e s , lo w e r th a n th o s e o f any o t h e r known ty p e o f compound. The ato m ic r e f r a c t i v i t y o f t h e f l u o r i n e atom v a r i e s w ith t h e ty p e o f com­ p ound; f o r a l i p h a t i c m o n o flu o rid e s i t i s 0 . 9 5 , and f o r p e r f lu o ro c a rb o n s i s i s 1 .2 3 t o 1 .2 5 . L ik e w is e , t h e i r d i e l e c t r i c c o n s ta n ts a r e somewhat lo w er th a n th o s e o f t h e c o rre s p o n d in g s a t u r a t e d h y d ro c a rb o n s . T h e ir d ia m a g n e tic s u s c e p t i b i l i t i e s a re a b n o rm a lly low and th e lo w e st u l t r a s o n i c v e l o c i t y y e t m easured i n l i q u i d s a t norm al te m p e ra tu re s h as been rec o rd ed in p e rflu o ro h e p ta n e . The f lu o r o c a rb o n s a r e p r a c t i c a l l y i n s o lu b le i n w a te r , anhydrous h y d ro g en f l u o r i d e , and h y d ro x y lic o rg a n ic s o l v e n t s . T h is l a s t f a c t h as 7 TABLE XI COMPARISON OF SOME PHYSICAL PROPERTIES OF FLUOROCARBONS AND HYDROCARBONS D e n s ity , g /m l B o ilin g P o in t M e ltin g P o in t cf4 -12 8°C -18U°C 1 .6 2 ch 4 -1 6 1 -1 8 6 0 .6 1 5 (.-166) CaF6 - 7 8 .3 -1 0 0 1 .2 9 1 (.-100) CaHs - 8 8 .3 -172 0 .5 6 1 (.-100) +29.3 - 1 2 5 .6 n— CgHi«j 3 6 .2 -1 3 1 .5 n-C7F 15 11-C 7R15 Compound (-130°C ) R e fra c tiv e In d e x D ie le c tric C o n s ta n t( 20°C) ----- ----- ----- ----- --------- ----- 1 .6 9 5 (+20) 1.2U5 1 .6 8 O.626 ( 20) 1 .3 5 7 0 1 .8 2 8 82.1* 1 .7 3 3 (2 0 ) 1.2 6 1 8 1 .7 6 5 9 8 .5 0 .6 8 6 (2 0 ) 1 .3867 1 .9 7 1 ij b e e n u t i l i s e d i n t h e i r p u r i f i c a t i o n , s in c e a lc o h o l e x t r a c t i o n rem oves much o f th e p a r t l y - f l u o r i n a t e d m a t e r i a l . F lu o ro c a rb o n s a re s l i g h t l y s o l u b l e i n h y d ro c a rb o n s and somewhat m ore s o lu b le i n e th n s and c h lo r o c a rb o n s * S in c e t h e f lu o r o c a rb o n s a r e c h e m ic a lly i n e r t , t h e i r p h y s i c a l p r o p e r t i e s have b e e n u t i l i s e d f o r p u r i t y d e te r m in a tio n s . A n a ly s is by i n f r a r e d m ethods i s v e r y u s e f u l s i n c e th e p re s e n c e o f iso m e rs c a n be d e te c te d . T h is i s im p o rta n t s in c e m aiy o f th e iso m e rs have e s s e n t i a l l y t h e same b o i l i n g p o i n t s . D e te rm in a tio n s o f d i e l e c t r i c c o n s ta n ts a re a ls o v a lu a b le a s a m eans o f c h e c k in g p u r i t y (1 6 ) . A co m p ariso n o f some o f th e p h y s ic a l p r o p e r t i e s o f th e f l u o r o c a r ­ bons and th e h y d ro c a rb o n s i s g iv e n i n T a b le I I . A more com plete l i s t o f t h e p r i n c i p a l p h y s ic a l p r o p e r t i e s o f th e known f lu o ro c a rb o n s and a more th o ro u g h d i s c u s s i o n o f them h a s b e e n p r e s e n te d b y B ric e (2 ) , and by H a s s e ld in e and Sharpe (1 7 ) . M o le c u la r p r o p e r t i e s . D e te rm in a tio n s o f bond d i s t a n c e s i n flu o r o c a rb o n s h av e r e s u l t e d i n a v a r i e t y o f v a lu e s f o r th e C-F and C-C b o n d s . It a p p e a rs c e r t a i n t h a t t h e C-F bond d is t a n c e i s n o t n e c e s s a r i l y th e same o o i n d i f f e r e n t m o le c u le s . V a lu e s o f 1 .3 3 A t o 1 .3 8 A have been r e p o r te d f o r th e bond d i s t a n c e i n t h r e e sim p le f l u o r o e t h a n e s . I n many c a s e s , s e r i o u s d i s c r e p a n c i e s e x i s t i n th e v a lu e s r e p o r te d f o r th e C-C bond o o d i s t a n c e . V a lu e s from 1.1*6 A (18) t o 1 .5 2 A (2 ) have b een r e p o r t e d , Q w h ile th e u s u a l v a lu e i n a l i p h a t i c h y d ro c a rb o n s i s 1 .5 5 A. A l i s t o f bond d i s t a n c e s , bond a n g le s , and bond e n e r g ie s o f some sim p le flu o r o c a rb o n s 9 i s p r e s e n te d i n T a b le H I . A more e x te n s iv e t a b l e o f bond d i s t a n c e s and bond a n g le s h a s b e e n co m p iled b y G lo c k le r (2 ) . The th e rm o c h e m is try o f t h e flu o r o c a rb o n s h a s n o t y e t b e en s t u d i e d t o any e x t e n t . The a v e ra g e C-F bond s t r e n g t h i n p e rflu o ro m e th a n e h a s b e e n fo u n d t o b e 1 0 9 .9 k c a l ./ u i o l e . H o o v e r , i t h as b e e n i n d ic a t e d t h a t t h e C-F bond i n a m o le c u le su c h a s m eth y l f l u o r i d e may be much w e ak e r. An e s tim a te o f b 9 .7 k c a l .^ n o l e b a se d on d ip o le moment d a t a h a s b e e n r e ­ p o r te d f o r t h e C-F bond i n t h i s compound ( 2 ) . L ik e w is e , t h e C-F bond e n e rg y i n d iflu o ro m e th a n e i s a p p ro x im a te ly 1 0 5 .3 k c a l .^ n o l e . H e a ts o f f o r m a tio n have b e e n e s tim a te d from th e above a p p ro x im a tio n s . As m ore in f o r m a tio n becom es a v a i l a b l e c o n c e rn in g bond e n e r g i e s , i n t e r n u c l e a r d i s t a n c e s , and f o r c e c o n s t a n t s , i t w i l l be p o s s i b l e t o d i s c u s s q u a n t i t a t i v e l y r e s o n a n c e , h y p e r c o n ju g a tio n , and s t e r i c e f f e c t s i n t h e f lu o r o c a r b o n s . D ip o le moments o f s e v e r a l f lu o r o c a rb o n s have b e e n d e te rm in e d . o f t h e s e a re l i s t e d i n T ab le IV . Some S in ce t h e d ip o le s i n f lu o ro c a rb o n s a r e v e ry c lo s e t o g e t h e r , th e y w i l l a f f e c t one a n o th e r by i n d u c t i o n . The g r e a t e r moment o f e t h y l f l u o r i d e compared t o m e th y l f l u o r i d e i s due to t h e moment in d u c e d on t h e se co n d c a rb o n by th e p r i n c i p a l d ip o le i n th e C-F b o n d . S eco n d ary a l k y l f l u o r i d e s have l a r g e r moments th a n p rim a ry f l u o r i d e s and t e r t i a r y f l u o r i d e s have l a r g e r moments th a n se c o n d a ry compounds ^19) . Smyth (20) h as s t u d i e d th e q u e s tio n o f in d u c tio n and re s o n a n c e from d ip o le moment d a t a . L eonard and S u tto n (21) have m easured d ip o le moments o f a ro m a tic f l u o r i n e compounds and u se d th e r e s u l t s t o e s tim a te bond a n g l e s . 10 TABLE I I I MOLECULAR CONSTANTS OP SCME FLUOROCARBONS C-F C-C FCF Bond D is ta n c e Bond D is ta n c e Bond Angle CH3F 0 1 .3 8 A ------ ----- c h *f 3 1*36 ----- 110° 1 0 S .6 CHF* 1 .3 3 ----- 109° 2 8 ' 1 0 3 .3 cf4 1 .3 6 ------ 109° 28* 1 0 9 .9 CFs -CH3 1 .3 7 0 1 .S 2 A 107° 30* ----- CHF2-CHF3 1 .3 3 1.1*6 108° O 108 ----- Compound CF3 -CF3 1 .5 1 E stim a te d C-F Bond Energy 8 9 .7 k c a l/m o l 11 TABLE IV DIPOLE MOMENTS OF SOME FLUOROCARBONS Compound D ip o le Moment R e fe re n c e M e th y l f l u o r i d e 1 .8 0 8 D 19 D if l u o r cme th a n e 1 ,9 3 22 T r i f l u o r ome th a n e 1.6U5 18 E th y l f l u o r i d e 1*92 19 1 ,1 - D if l u o r o e th a n e 2 . 2U 23 1 , 1 ,1 - T r i f l u o r o e t h a n e 2 .3 2 1 2h H exaf l u o r oe th a n e 0 .0 25 T r i f l u o r o a c e t i c a c id 2 .2 8 23 3 , 3 , 3- T rif lu o r o p r o p y n e 2 .3 6 18 C y c lo p e n ty l f l u o r i d e 1 .8 6 26 n-Amyl f l u o r i d e 1 .8 5 27 rv-Perf l u o r op e n t ane 0 .0 23 is o - P e r f lu o r o p e n ta n e 0 .0 23 12 III. THEORETICAL BACKGROUND I n 1 9 1 2 , P e t e r Debye (2 8 ,2 9 ) p o s t u l a t e d th e e x is te n c e o f perm anent e l e c t r i c d ip o le moments i n c e r t a i n m o le c u le s and d e v elo p ed t h e th e o r y w hich h a s b e e n t h e b a s i s f o r a l l su b se q u e n t d ip o le moment w ork. Debye*s t h e o r e t i c a l tr e a tm e n t i s b r i e f l y o u t li n e d b e lo w . When a d i e l e c t r i c m a t e r i a l i s p la c e d betw een th e p l a t e s d e n s e r, th e c a p a c ita n c e i s c o n s ta n t o f t h e medium. in c r e a s e d by a f a c t o r o f a con­ €. , th e d i e l e c t r i c The c a p a c ita n c e C o f a c o n d en se r w ith a d i ­ e l e c t r i c b etw een th e p l a t e s i s g iv e n by C <= € C0 w here C0 i s t h e c a p a c ita n c e o f th e c o n d e n se r w ith a. vacuum betw een th e p la te s . S in c e t h e c h a rg e s on th e p l a t e s a re u n c h a n g e d , th e o r i g i n a l e l e c t r i c f i e l d E0 betw een t h e p l a t e s i s re d u c e d by th e f a c t o r e , so th a t E g iv e s th e new e l e c t r i c f i e l d £ . . Eo £ The f i e l d i s re d u c e d b e cau se th e i n ­ d u ced d ip o le s a r e a lig n e d so a s t o p ro d u ce an o v e r - a l l d ip o le moment t h a t c u t s down th e f i e l d s t r e n g t h . The v e c to r q u a n tity F c a l l e d th e p o l a r i z a t i o n v e c to r i s th e d ip o le moment p e r u n i t volum e, and re d u c e s th e n e t c h a rg e . Prom E q u a tio n s 2 and 3 w hich com bined w ith E q u a tio n 6 g iv e s w hich i s known as th e C la u s iu s - M o s o tti E q u a tio n . M u ltip ly in g b o th s i d e s o f t l i i s e q u a tio n b y th e r a t i o o f m o le c u la r w e ig h t t o d e n s i t y M /d, g iv e s I € - 1) K ( € + 2) d w here th e q u a n t i t y _ it t t nH c< 0 3 d ^ k r t to * C Q (7 ) 3 i s c a l l e d th e m o la r in d u ce d p o l a r i z a t i o n , and i n c l u d e s c o n t r i b u t i o n s from in d u c e d d ip o le s o n ly . I n o r d e r t o o b ta in t h e t o t a l m o la r p o l a r i z a t i o n & term due t o th e p erm an en t d ip o le s m u st be a d d e d . The in d u c e d moment i s in d e p e n d e n t o f te m p e ra tu re s i n c e , i f th e m o le c u la r p o s i t i o n i s d i s t u r b e d by th e rm a l c o l l i s i o n s , t h e d ip o le i s a t once in d u c e d a g a in i n th e f i e l d d i r e c t i o n . The c o n t r i b u t i o n t o th e p o l a r i z a t i o n c a u se d b y th e perm anent d i p o l e s , how ever, i s sm aller* a t h ig h e r te m p e ra tu re s s i n c e th e random th e rm a l c o l l i s i o n s o f th e m o le c u le s oppose t h e te n d e n c y o f t h e d ip o le s t o l i n e up i n th e e l e c t r i c f i e l d . F o r a p e rm an en t d ip o le i n th e a b se n c e o f a f i e l d , a l l o r i e n t a t i o n s a r e e q u a lly p r o b a b l e , and th e number o f d ip o le s d i r e c t e d w ith in a s o l i d 15 a n g le d u> i s A d u) , w here A i s a c o n s ta n t d e p en d in g on th e number o f m o le c u le s u n d e r o b s e r v a t i o n . I f a d ip o le moment p i s o r i e n t e d a t an a n g le 0 t o a f i e l d s t r e n g t h F , i t s p o t e n t i a l e n e rg y i s U * - mF cos 0. A c co rd in g t o th e B oltsm ann d i s t r i b u t i o n ls w , th e number o f m o le c u le s o r i e n t e d w ith in th e s o l i d a n g le d u) i s U kT A e dud A e mF co s O/kT ' du) and t h e a v e ra g e v a lu e o f th e d ip o le moment i n th e d i r e c t i o n o f th e f i e l d can b e shown t o be / aF co s 9 /k T Jk e > lc o s © d u i m ( 8) p iF cos 0 /k T A e du) To e v a lu a te t h i s e x p r e s s io n , l e t >xF * x and cos © * y {9) kT th e n d tO » 2 tt s i n © d © * 2 tt dy. (1C) S u b s t i t u t i n g E q u a tio n s 9 and 10 i n E q u a tio n 8 g iv e s '+1 ydy m * I i L I t ----------------(* i xy , e dy -1 ) = c o th x 1 x L (x) 16 w h e r e L (X ) is know n a s t h e L a n g e v i n f u n c t i o n . x I n m o st c a s e s , u F lZ __ = kT i s a v e ry s m a ll number s o t h a t on ex p an d in g L (x ) i n a power s e r i e s , o n ly t h e f i r s t term n eed be r e t a i n e d , le a v in g 2 L (x ) - 3 and m - . f 3kT The t o t a l p o l a r i z a b i l i t y oC o f a d i e l e c t r i c i s found by a d d in g th e o r i e n t a t i o n p o l a r i z a b i l i t y , due t o th e perm anent d i p o l e s , t o t h e d i s ­ t o r t i o n p o l a r i z a b i l i t y , and may be w r i t te n - °C0 + pLa/ 3kT . The t o t a l p o l a r i z a t i o n i s t h e r e f o r e U IT PM U * N ■ —“ 3------ ( ) w here PM i s t h e t o t a l m o la r p o l a r i z a t i o n . th e Debye e q u a t io n . (11) T h is e q u a tio n i s known a s Com bining t h i s w ith th e C la u s iu s - M o s o tti E q u a tio n (E q u a tio n 7) g iv e s pm , ( £ - 1) M ----------------- . l £ + 2) d 1+n W ------------- ( ) . The c r y s t a l r e p la c e d th e tu n in g c i r c u i t fo u n d i n m ost o s c i l l a t o r s and th u s th e o s c i l l a t o r r e q u ir e d no tim in g a d ju s tm e n t and would work w ith ­ o u t change o f com ponents o v e r a w ide ran g e o f c r y s t a l f r e q u e n c i e s . 25 m> \A /w V ap p aratu s. \ a a —| ^ II I I I —K A A A t Circuit h 2. h i of the heterodyne-beat w .. LL1 Ls;__ > A A A A ^ \ A A A a - —^ ^ 'A A — M| f U lM J U Figure -w 26 F igu re 2 . (co n tin u ed ) Legend R e s is to rs C ondensers R1 3 3 ,0 0 0 ohms Cl 0 .0 0 5 / i f m ica R2 2 2 ,0 0 0 ohms C2 ,c 5 ,c i5 0 .1 /A,f 6 0 0 -v o lt p a p e r R3,R]+,R18 R20,R12 C3,C8 335 MM-f v a r . a i r cond . 0 .1 megohm . c4 25 MA f m ica R£,R9,R20 R 17,R 21, 4 7 ,0 0 0 ohms 06 0 -5 0 R6 680 dims C7 175 R7 6800 ohms C9 0 .0 1 0 R 8 ,R l4 1 5 ,0 0 0 ohms c i o ,c i4 0 .0 0 5 A A f 5 0 0 - v o lt p a p e r R ll 2 7 ,0 0 0 ohms C11,C18,C19 0 *01 M- f 6 0 0 - v o lt p a p e r R13 150 ohms C12 10 R15 8 2 ,0 0 0 ohms C13 0 .0 0 2 5 M- f m ica R16 2 5 ,0 0 0 ohms C16 0 .2 5 R19 2000 ohms C17 10 R22 C20 300 R23 0 .5 megohm p o te n tio m e te r 1 megohm C21 4 R24 4 ,7 megohm M-M-'f a i r trim m er A A f v a r . a i r cond. K f m ica decade A f 450- v o l t e l e c t r o l y t i c A f 6 0 0 -v o lt p a p e r A f 2 5 -v o l t e l e c t r o l y t i c a f m ica A f 450- v o l t e l e c t r o l y t i c M is c e lla n e o u s 3 1 ,3 2 S.P.S.T . PS1 S o c k e t f o r c o a x ia l w ir e c o n n e c tio n t o d i e l e c t r i c PS2 S o c k e t f o r c o a x ia l w ir e c o n n e c tio n t o J Phone ja c k f o r le a d t o c a th o d e -r a y o s c illo s c o p e s w itc h e s c e ll sta n d a r d c o n d e n se r 27 > OpQ CO u O CM cd rH CO W ( i *H *r4 ft W^ S3 © is: w^ w S -r ~ © w ts *q O <3 O T0)3 CM 25 A a 5 bO (D 6 co > A / W v — L-A A A A t 8 T -A 8 i_r\ P *H 0> S CM Xi P O P P •H H O CO O *o cd & ^ o Q CO •H CO E l cp O O rH x: P O *M CO o 'S • CO CO cr\ © ca X3 o p 0CQ CO 6h • JU co X ! CQ P sO MJUJUUUJUU UUL n n rm w n m n > / O ♦ o rH • pH Cd i CQ 28 S in c e e x c i t a t i o n o th e rw is e was n o t a d j u s t a b l e , th e c o n d en se r C3 F ig u r e 2) was r e q u i r e d t o o b t a i n s a t i s f a c t o r y o p e r a t i o n . The 6SJ7 p e n to d e tu b e was u se d a s a t r i o d e o s c i l l a t o r , w ith th e c a th o d e and s u p p r e s s o r g r i d g ro u n d ed . T h is p r o v id e d s c r e e n in g a g a in s t c a p a c ita n c e c o u p lin g o f t h e o s c i l l a t o r t o l a t e r s t a g e s , so t h a t th e fre q u e n c y o f o s c i l l a t i o n was l e s s a f f e c t e d by fe e d b a c k th ro u g h th e p l a t e . Each o s c i l l a t o r was s h i e ld e d by e n c lo s u r e i n a s e p a r a te m e ta l box and t h e s i g n a l o u tp u t o f e a c h was f e d t o th e m ix e r tu b e th ro u g h co­ a x ia l le a d s . aluminum b o x . Th© e n t i r e a p p a ra tu s was e n c lo s e d i n a th e r m a lly i n s u l a t e d T em p era tu re c o n t r o l o f t h e a p p a ra tu s was p ro v id e d f o r , b u t was n o t found t o i n c r e a s e th e s t a b i l i t y o f th e b e a t- f re q u e n c y o u t­ p u t. P r e c i s i o n C ondenser A G e n e ra l R adio Type 722-N p r e c i s i o n c o n d e n s e r, w ith a c a p a c ita n c e r a n g e o f 1100 m ic ro m ic ro f a ra d s was u se d as th e s ta n d a r d c o n d e n s e r. S in ce th e c a p a c ita n c e in c re m e n ts m easured w ere l e s s th a n fo u r m ic ro m ic ro f a r a d s , i t was n e c e s s a r y to p la c e th e p r e c i s i o n c o n d e n se r i n s e r i e s w ith a n o th e r c o n d e n s e r, th e r e b y d e c r e a s in g th e e f f e c t i v e c a p a c ita n c e o f t h e s ta n d a rd from 110O t o U m ic ro m ic ro f a r a d s . T h a t was th e r o l e o f th e co n d en se r C7 i n F ig u re 2 , a v a r i a b le c o n d en se r w ith a lo c k s e t t i n g and w ith a maximum c a p a c ita n c e ©f 175 m ic ro m ic ro f a r a d s . The t o t a l c a p a c ita n c e C o f th e s ta n d a r d co n d en se r Cg p lu s th e a i r c o n d e n se r C7 i s g iv e n by th e e q u a tio n 29 C S + c 7 w hich shows t h a t th e r e a d in g on t h e s ta n d a r d c o n d e n se r would be v e ry n o n - l in e a r w ith th e t o t a l c a p a c ita n c e c h a n g e , s in c e Cg was a s l a r g e o r l a r g e r t h a n C7 . T h is was h ig h ly u n d e s ir a b le and to av o id t h i s , a c o n d e n se r (C 9 i n F ig u re 2) o f r e l a t i v e l y l a r g e c a p a c ita n c e was p la c e d i n p a r a l l e l w ith th e s ta n d a r d c o n d e n s e r. T h is had th e ad v an tag e t h a t one s i d e o f b o th t h e m ic a and s ta n d a rd co n d en se r w ere grounded* C9 was a G e n era l R ad io Type 38O-N m ica decade c o n d e n se r w ith a c a p a c ita n c e ra n g e o f 0 .0 1 t o 0 .0 0 1 n i c r o f a r a d s . W ith t h i s arra n g em e n t th e t o t a l c a p a c ita n c e o f t h e t h r e e c o n d e n se rs i s (Cg + C9 + C7 ) and d i f f e r e n t i a t i o n w ith r e s p e c t to Cg g iv e s dC = dCg C7 (Cg + C9 + C 7 ) 2 Thus i f C9 i s l a r g e com pared t o Cg th e change o f th e t o t a l c a p a c ita n c e w ith r e s p e c t t o t h e s ta n d a r d co n d en ser s c a l e w i l l be much more l i n e a r t h a n i n th e p r e v io u s c a s e . The c a l i b r a t i o n curve f o r th e s ta n d a rd c o n d e n se r ( F ig u r e 5) i n d i c a t e s th e ap p ro ach t o l i n e a r i t y a ch ie v e d by t h i s c o m b in a tio n o f c o n d e n s e r s . By v a r i a t i o n o f t h e c a p a c ita n c e o f C7 and C9 th e s ta n d a r d c o n d en se r c o u ld be made t o c o v e r any c a p a c ita n c e ra n g e from around one up to e le v e n -h u n d re d m ic ro m ic ro f a r a d s . F o r t h i s i n v e s t i g a t i o n C9 was s e t a t 30 0,001* m ic r o f a r a d s and C7 a d ju s te d su ch t h a t 1 0 ,0 0 0 d i a l u n i t s on t h e s ta n d a r d c o n d e n se r r e p r e s e n te d a c a p a c ita n c e change o f 3 .7 0 0 a i c r e m ic ro f a ra d s , o r a p p ro x im a te ly 0 .0 0 0 3 m ic ro m ic ro f a ra d s p e r d i a l u n i t . C a l i b r a t i o n o f P r e c i s io n C ondenser A p rim a ry s ta n d a r d c a p a c i t o r b u i l t by J . L . S p e ir s from a d e s ig n by C onner (1*7) was u s e d f o r th e c a l i b r a t i o n o f th e G e n e ra l R adio p r e c i s i o n c o n d e n s e r. in P la te I . T h is p rim a ry s ta n d a r d i s shown i n F ig u r e h and I t c o n s i s t e d o f a c o a x i a l c y li n d e r arra n g em e n t su ch t h a t a c e n t e r r o d , th e o p p o s ite ends o f w hich were i n s e r t e d i n c y li n d e r s o f d i f f e r e n t d i a m e t e r s , c o u ld be moved a lo n g i t s a x is t o p ro d u c e m in u te c a p a c ita n c e c h a n g e s . The c a p a c ita n c e change p e r in c h o f t r a v e l was c a l c u l a t e d from t h e geom etry o f th e c a p a c i t o r w ith a maxim inn e r r o r o f l e s s th a n one p e r c e n t . The in n e r ro d tu r n e d on a th r e a d e d c e n t e r b lo c k and t h e drum a t t h e c e n t e r was r u l e d w ith 11*00 u n i t s p e r i n c h . The c a p a c ita n c e change p e r in c h o f t r a v e l was 1.1*800 m ic ro m ic ro fa ra d s , or 0.0 0 0 1 0 ^7 m ic ro m ic ro f a ra d s p e r drum u n i t . The one p e r c e n t maximum e r r o r would n o t a f f e c t th e d i e l e c t r i c c o n s ta n t m easurem ents a s lo n g as th e r e l a t i v e v a lu e s o f th e c a l i b r a t i o n u n i t s w ere c o n s t a n t , s in c e th e d i e l e c t r i c c o n s t a n t depends on th e r a t i o o f two c a p a c ita n c e m ea su re ­ m e n ts . W ith t h i s i n m in d , th e c a l i b r a t i o n o f th e G e n e ra l R adio p r e c i s i o n c o n d e n se r was acco m p lish ed u s in g th e c e n t e r p o r t io n ©f th e s c a l e on th e p rim a ry s ta n d a r d c a p a c i t o r , s in c e i t was shown t h a t t h i s was t h e m ost l i n e a r p a r t o f th e s c a l e . 31 1 2 3 h In c h e s 5 / k XX XXA X X X X A >W To C lF a S u p p ly o — A To Mech. Pump F ig u re 9 . Vacuum system f o r h a n d lin g h alo g en f l u o r id e s (Vacuum L in e I I ) . A ,B C D E F G H * M onel t r a p s f o r d i s t i l l i n g and s t o r i n g h a lo g e n f l u o r i d e s H e lic o id p r e s s u r e gages 0-7 6 0 mm. o f m ercury Monel d i e l e c t r i c c e l l ( C e ll I I ) . A b so rb in g b o t t l e , f i l l e d w ith s o d a - lim e . G lass c o l d - t r a p f o r pump p r o t e c t i o n M ercury d i f f u s i o n pump C o n n e ctio n to Vacuum L ine I E l e c t r i c a l l y h e a te d n ic k e l tu b in g G la ss tu b in g & M e ta l s to p c o c k s , p h o sp h o r-b ro n z e b e llo w s ® G lass vacuum sto p c o c k s la a s e p a r a te h a n d lin g s y s te m . When p la c e d i n t h e p o s i t i o n shown , c h l o r ­ in e t r i f l u o r i d e c o u ld be p a sse d th ro u g h th e system to remove sm a ll amounts o f w a te r o r o t h e r c o n ta m in a n ts w hich m ig h t be p r e s e n t , and w ith w hich th e h a lo g e n f l u o r i d e s would r e a c t . The Bourdon tu b e i n th e H e lic o id gage was e l e c t r i c a l l y h e a te d t o th e same te m p e ra tu re as th e o t h e r p a r t s o f t h e m e ta l sy s te m . B e fo re e a c h d i e l e c t r i c c o n s ta n t m easurem ent th e p r e s s u r e gage was c a l i b r a t e d a g a in s t t h e manometer shown i n F ig u r e 8 , u s in g d ry a i r a s a so u rc e o f p r e s s u r e . The two vacuum sy ste m s w ere c o n n e c te d th ro u g h th e s to p c o c k H shown i n F ig u re 9 . D u rin g c a l i b r a t i o n o f b o th th e p r e s s u r e gage and d i e l e c t r i c e l l , th e s to p c o c k s I and J w ere tu r n e d t o b y -p a s s th e h a lo g e n f l u o r i d e a b so rb in g b o ttle . The p r e s s u r e c a l i b r a t i o n was d ep en d en t on th e a tm o sp h e ric p r e s s u r e ; th e re fo r© th e gage had t o be c a l i b r a t e d b e fo re e a c h s e r i e s o f ru n s. C a l i b r a t i o n c u rv e s w ere re p ro d u c e a b le o v e r a p e r io d o f an h o u r o r m ore t o w ith in - 1 rnn. o f m e rc u ry . The gage was alw ays c a l i ­ b r a t e d a t th e te m p e ra tu re a t w hich th e m easurem ents were t o be made. The h a lo g e n f l u o r i d e upon xdxich m easurem ents w ere b e in g made was s t o r e d i n t r a p B , and t r a p A, which was k e p t c o ld w ith Dry I c e - i s o p r o p a n o l m ix tu r e s , was u sed t o w ithdraw t h e v ap o r d u rin g a m easurem en t. I t was im p o s s ib le t o rem ove th e l a s t t r a c e o f th e c o r r o s iv e v a p o rs by t h i s m eans, and th e y w ere pumped o u t th ro u g h th e a b so rb in g b o t t l e E . T h is p a r t o f th e system was g l a s s , and c o rr o s io n i n sto p c o c k I n e c e s s i ­ t a t e d i t b e in g r e p la c e d o c c a s i o n a l l y . 12 T em p eratu re M easurem ent and C o n tro l T e m p e ra tu re -C o n tro lle d B a th I A sc h e m a tic r e p r e s e n t a t i o n o f th e r e l a t i v e p o s i t i o n s o f C e l l I and th e v a r io u s e le m e n ts o f th e h e a tin g system i n th e b a th i s shown i n F ig u r e 1 0 . The b a th was c o n ta in e d i n a co p p er c an w hich p ro v id e d an e l e c t r o s t a t i c s h i e l d f o r th e d i e l e c t r i c c e l l . The l i q u i d u se d i n th e b a th was A ro c h lo r 12U 8,1 a c h lo r i n a t e d b ip h e n y l w hich i s l i q u i d from b e lo w room te m p e ra tu re t o above 300°C. S ince i t i s a good d i e l e c t r i c , t h e h e a tin g w ir e s c o u ld b e wound d i r e c t l y i n th e b a t h . T h is b a th was u se d from room te m p e ra tu re t o around 100°C . T e m p e ra tu re -C o n tro lle d B a th I I The te m p e r a tu r e - r e g u la te d b a th u se d f o r th e h ig h te m p e ra tu re work i s i l l u s t r a t e d i n F ig u re 1 1 . t h e one d e s c r ib e d a b o v e . T h is b a th was c o n s id e r a b ly l a r g e r th a n The same l i q u i d was u sed f o r th e h e a tin g m edium , w ith k n if e h e a t e r s s e r v in g as th e h e a tin g e le m e n ts . An a u x i l i a r y h e a t e r o f 5 0 0 -\jbX>Xj c a p a c ity was u sed i n c o n ju n c tio n w ith th e 2 ^ 0 -w a tt h e a t e r , t o r e l i e v e th e lo a d c o n t r o l l e d by th e th e rc n o re g u la to r a t h ig h te m p e ra tu re s . The v o lta g e t© th e £0O -w att h e a t e r was a d ju s te d a t e ac h te m p e ra tu re su ch t h a t o n ly a s m a ll amount o f r e g u la te d c u r r e n t th ro u g h th e 2 5 0 -w a tt h e a t e r was needed to m a in ta in th e te m p e ra tu re a t t h e d e s i r e d v a lu e . C e ll I I r e q u ir e d a s m a ll amount o f f lu o r o th e n e wax 1 M onsanto C hem ical C o ., S t . L o u is , Mo. 143 CO F ig u re 1 0 . T e m p e ra tu re -re g u la te d b a th (B a th I ) f o r g la s s - e n c lo s e d d i e l e c t r i c c e l l ( C e ll I ) . A B C D £ F G H I,M J K L Wooden o u te r box F o a m -g la ss i n s u l a t i o n C opper c o n ta in e r f o r b a th l i q u i d M ycalex s t r i p s f o r h o ld in g h e a te r w ire s Nichrome h e a t in g w ire s t h a t a re c o n n e c te d to G G la ss s t i r r e r H e a te r c o n n e c tio n t o te m p e ra tu re r e g u l a t o r D i e l e c t r i c c o n s ta n t c e l l Therm ocouple w ire s G lass c o n n e c tio n to vacuum system C o a x ia l c o n n e c to r from c e l l le a d s t o h e te ro d y n e b e a t a p p a ra tu s T h e rm is to r uu F ig u re 1 1 . T e m p e ra tu re -re g u la te d B ath I I f o r C e ll I I . A Wooden o u te r b a th B G la ss c o tto n i n s u l a t i o n C G la ss j a r D 5 0 0 -w a tt a u x i l i a r y h e a tin g k n i f e , n o t c o n tr o l le d by re g u la to r E M e ta l s t i r r e r F T h e rm is to r G ,J T herm ocouples H C e ll I I I C o a x ia l le a d t o h e te r o d y n e -b e a t a p p a ra tu s K 2 5 0 -w a tt h e a tin g k n i f e , c o n tr o l le d by r e g u l a t o r L W a te r-c o o le d b r a s s c o v er M M e ta l c o n ta in e r e n c lo s in g d i e l e c t r i c c e l l U5 t o make i t v a c u u m - tig h t. A ro c h lo r 12^8 i s an e x c e l l e n t s o lv e n t f o r a n y th in g o r g a n ic i n n a t u r e , and was found t o d i s s o l v e th e f lu o r o th e n e wax and l e a k i n t o th e c e l l . To p r e v e n t t h i s , t h e c e l l was e n c lo se d i n a m e ta l c o n ta in e r and th e whole a ssem b ly was p la c e d i n th e b a t h . W ith t h i s a rra n g e m e n t, te m p e r a tu re c o n t r o l o f th e c e l l was e x c e l l e n t , even w ith an a i r sp a ce b e tw ee n i t and th e b a th l i q u i d . The o n ly d isa d v a n ta g e was th e l e n g t h o f tim e r e q u ir e d f o r th e c e l l t o a t t a i n th e e q u ilib riu m te m p e r a tu r e , w hich was u s u a l l y s l i g h t l y below t h a t o f t h e b a t h . The v a p o rs o f A ro c h lo r 121*8 a re t o x i c and q u i te c o rr o s iv e to p a in t s , v a rn is h e s , e tc . To red u c e th e amount o f v a p o r iz a tio n o f th e A ro c h lo r 12l*8 i n t o th e room , a w a te r-c o o le d c o v er was p la c e d on th e b a t h , and an a i r b lo w e r p u lle d th e re m a in in g v a p o rs i n t o th e hood. U nder t h e s e c o n d i t i o n s , th e b a th c o u ld be s a f e l y h e a te d t o 200°C o r s l i g h tl y above. The T h e rm o re g u la to r The c i r c u i t shown i n F ig u re 12 was an a d a p ta tio n o f a therm o­ r e g u l a t o r d e s ig n e d by B u rw e ll, P e te r s o n , and Kathmann (1*9) • The t e m p e r a t u r e - s e n s i t iv e e le m e n t was a th e m is to r x i n a W heatstone b rid g e c i r c u i t , w h ile th e h e a t e r c u r r e n t was c o n tr o lle d by means o f a s a t u r ­ a b le r e a c t o r i n s e r i e s w ith th e h e a t e r . With t h i s r e g u l a t o r , and th e b e th s d e s c r ib e d above, th e te m p e ra tu re o f e i t h e r c e l l c o u ld be con­ t r o l l e d t o l e s s th a n - 0.05>°C, ty p e lljJB t h e r m i s t o r , m an u fa ctu red by th e W estern E l e c t r i c Company, New Y ork, N. Y. was u se d . 1 A h6 1 OK tA A A o " ,:ri 0.05 6 S J 7 i= - H r 0,05 0.25 F il. d >

M easurem ents a t 89.5°C 28 75 126 175 252 329 I*oi 1*81 559 61*9 700 735 703 656 605 557 1*80 1*01* 332 253 176 87 37 <1 203.2 211*. 6 227.2 238.1* 257.3 275.2 292.8 3 1 2 .1* 3 3 0 .8 352.8 365.8 3 7 2 .8 0.1*81* 0.531* 0.5 9 1 0.61*1 0 .7 2 1 0 .7 9 8 0 .8 7 2 0 .9 5 1 1 .0 2 6 1.111* 1.161* 1 .1 9 5 32 103 199 308 1*02 505 681 735 699 628 533 1*25 331 229 55 <1 2 0 2 .9 2 2 0 .9 21*3.3 2 6 9 .6 292.8 3 1 8 .0 360.1 371.9 0.1*82 0 .5 6 3 0 .6 6 1 0.7 7 3 0 .8 7 2 0 .9 7 1 1.11*5 1 .1 9 5 38 101 185 300 1*02 503 595 683 735 692 630 51*7 1*33 331 231 11*0 52 <1 2 0 3 .9 2 2 0 .1 21*0.0 2 7 7 .6 2 9 2 .6 3 1 7 .6 339.7 361.7 371* .3 0.1*86 0 .5 6 1 0.61*7 0 .6 0 7 0.8 7 1 0 .9 7 3 1.062 1 .1 5 0 1 .2 0 0 61 TABLE V I ( CONTINUED) P re ssu re H e lic o id Gage mm o f Hg P r e c i s io n C ondenser R eading C a p a c ita n c e M easurem ents a t 1 0 1 .8°C 701 638 533 459 394 326 261 165 69 <1 151.2 165 .1* 1 8 8 .8 205.7 219.lt 23lt .2 21*8.8 2 7 0 .5 2 9 2 .6 3 0 8 .1 0 .2 5 1 0 .3 1 5 0.1*19 0.1*95 0.557 0 .6 2 3 0.681* 0 .7 7 7 0 .8 7 1 0.931* 3k 99 200 277 399 431 519 595 674 734 695 630 530 453 372 300 213 138 59 <1 11*8.7 1 6 3 .0 1 8 5 .7 2 0 2 .1 2 2 0 .1 235.9 2 5 5 .6 2 7 2 .6 2 9 1 .0 301*.7 O.238 0 .3 0 5 0 . 1*05 0.1*79 0 .5 6 0 0 .6 2 9 0 .7 1 3 0 .7 8 2 0.861* 0 .9 2 0 37 118 210 318 401 510 595 675 734 692 611 520 412 330 221 138 58 <1 11*8.1* 1 6 6 .2 1 8 6 .6 2 09.9 2 2 8 .6 252.9 2 7 1 .6 290.1* 3 0 3 .1 0 .2 3 8 0 .3 1 9 0.1*09 0 .5 1 3 0 .5 9 8 0 .7 0 1 0.782 0 .8 6 2 0.911* 28 91 197 272 337 405 kio 568 664 734 62 TABLE V I (CONTINUED) P re ssu re H e lic o id Gage inro. o f Hg P r e c i s io n C ondenser R eading C a p a c ita n c e M easurem ents a t 1 1 5 .8°C Cl 11*7.8 1 6 3 .6 183.1* 2 0 7 .7 2 2 5 .6 21*6.6 2 6 6 .1 2 8 3 .9 2 93.5 0.23U 0.307 0 .3 9 5 0.501* 0 .5 8 5 0 .6 7 5 0 .7 5 7 0.831* 0 .8 7 5 37 100 207 311* 1*03 512 60$ 691 732 690 621 £22 1*17 328 220 127 h2 <1 11*8.1* 1 6 1 .7 183.7 2 0 5 .9 221*. 7 21*7.1* 2 6 6 .5 281*.8 293.3 0 .2 3 8 0 .2 2 9 0 .3 9 7 0.1*96 0 .5 8 0 0 .6 7 9 0.760 0 .838 0 .8 7 5 23 116 206 318 1*10 512 603 680 732 703 611 523 1*12 321 220 129 53 11*5.2 161*.0 1 8 3 .0 2 0 5 .9 225.0 21*6.7 2 6 6 .0 2 8 2 .0 292.8 0.222* 0 .3 0 9 0 .3 9 5 0.2*95 0 .5 8 2 0 .6 7 6 0 .7 5 8 0 .8 2 6 0.8 7 2 32 109 201 322 U08 £08 600 686 732 69U 618 £28 1*08 323 223 133 hi Cl 63 TABLE V I (CONTINUED) P ressu re H e lic o id Gage mm„ o f Hg P r e c is io n Condenser Reading C apacitance KHf Measurements a t 1 2 9 .2°C 35 108 202 297 1*01 506 609 698 727 683 611 518 1*25 321 218 112 30 <1 lUO.U 15U.2 1 7 2 .6 1 9 0 .1 210.3 2 3 0 .6 2 5 0 .6 2 6 7 .2 27U.3 0 .2 0 1 0 . 26 U 0.3U6 0 . 1*26 0 .5 1 6 0 .6 0 7 0 .6 9 2 0 .7 6 3 0.79U 31 108 202 310 1*07 510 610 690 727 687 611 518 1*12 316 211* 116 37 <1 1 3 3 .9 lU 8 .lt 1 6 6 .U 1 8 6 .U 2 0 5 .9 2 2 6 .0 2 UU.8 2 6 0 .8 268 .U 0 .1 7 0 0 .2 3 8 0 .3 2 0 0.U05 O.U95 0 .5 8 6 0 .6 6 7 0 .7 3 6 0 .7 6 9 Measurements a t 1UU.1 °C 32 108 215 310 1*11 500 589 680 725 39 113 203 311 1*02 506 601 681 725 685 610 505 311 223 135 1*5 <1 191. U 206.1 225.7 2U3.7 2 6 2 .2 279.2 2 9 5 .U 312 .U 32 0 .8 0.U31 O.U97 0 .5 8 5 0 .6 6 3 0 . 7 U2 0 .8 1 5 0 .8 8 3 0 .9 5 1 0 .9 8 5 679 605 517 1*10 320 217 122 1*3 <1 1 8 9 .U 203 .U 220 .U 21*0.2 2 5 7 .1 276.7 29U.6 309 .U 3 1 7 .6 0.U22 0.U85 0 .5 6 1 O . 6U8 0 .7 2 0 0.802 0 .8 7 9 0 .9 3 9 0.972 Un 6h TABLE V I ^CONTINUED) P re ssu re H e lic o id Gage mm. o f Hg P r e c is io n C ondenser R eading C a p a c ita n c e Me asurem e n ts a t 1 5 7 .7°C 31 111 200 311 U09 505 692 725 30 100 206 310 i*i8 906 593 682 725 32 112 199 311 !±06 502 600 685 725 686 607 520 1*11 311* 218 33 <1 11*8.1* 1 6 2 .5 177 .3 196.2 212.8 2 2 9 .6 2 6 1 .6 267.1* 0 .2 8 3 0 .3 0 3 0 .3 6 9 0.1*53 0 .5 2 7 0 .6 0 1 0 .7 3 9 0.761* 687 618 513 1 3 8 .0 1 5 0 .5 1 6 8 .0 1 6 6 .1 201, .1 2 1 9 .8 231* .8 250.1* 2 5 7 .6 0 .1 9 0 0.21*8 0 .327 0.1*08 0.1)88 0 .5 8 8 0.627 0 .6 9 1 0 .7 2 2 132.3 11,6.6 1 6 1 .6 1 80.3 1 9 6 .5 213.9 2 3 0 .5 2 3 5 .0 251.8 0.161* 0 .2 2 9 0 .2 9 8 0 .3 8 2 0.1*51* 0.5 3 2 0 .6 0 6 0 .6 6 9 0 .697 Ull 301* 217 131 1*3 <1 685 60 6 521 lao 316 221 123 Uo <1 65 TABLE V I I DATA FOR THE CALIBRATION OF THE GENERAL RADIO PRECISION CONDENSER U n its on P r e c i s io n C ondenser U n its on P rim a ry S ta n d a rd C a p a c ito r m A 97 .1* 1 0 8 .1 1 1 9 .8 1 3 1 .1 11*2.6 151* .2 1 6 5 .0 1 7 8 .0 1 8 9 .9 2 0 1 .5 2 1 3 .3 110O 1150 1200 1250 1300 1350 11*00 11*50 1500 1550 1600 0 50 100 is o 200 250 300 350 1*00 1*50 500 0 .0 5 .2 8 10.57 1 5 .8 5 21.11* 26.1*2 3 1 .7 1 36.99 1*2.28 1*7.56 52.85 2 1 3 .3 22U.9 2 3 7 .1 21*9.1 2 6 2 .0 27U.2 2 8 6 .8 2 9 9 .3 3 1 2 .7 32 5 .lt 3 3 9 .0 3 5 2 .1 3 6 5 .0 3 7 7 .7 3 9 1 .lt 1*03.9 1*17.5 1*3 0 .2 1*1*3.7 1*55.8 1*69.5 1000 1050 1100 1150 1200 1250 1300 1350 11*00 11*50 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 11*00 11*50 1500 5 2 .8 5 58.13 6 3 . 1*2 68.70 7 3 .9 9 79.27 81* .56 89.81* 95.13 100 . l a 1 0 5 .7 0 1 10.98 116.27 1 2 1 .5 5 126.81* 132.12 137 .1*1 11*2.69 11*7 .98 1 5 3 .2 6 158.55 1*69.5 1*83.3 1*96.1* 5 1 0 .3 521*. 6 5 3 8 .9 5 5 3 .2 567.1* 1000 1050 1100 1150 1200 1250 1300 1350 1500 1550 1600 1650 1700 1750 1800 1850 158.58 1 63.83 169.12 171*. 1*0 1 7 9 .6 9 181*. 97 1 90.25 195.51* C a p a c ita n c MM? x 66 TABLE V II (CONTINUED U n its on P re c is io n C o n d en ser U n its on P rim ary S ta n d a rd C a p a c ito r * A 5 8 2 .0 5 9 6 .2 61 1 .2 625.7 6U0,8 6 5 5 .9 6 7 0 .8 6 8 5 .1 7 0 0 .9 7 1 5 .3 7 3 1 .1 71*5.1* 7 6 0 .9 11*00 il*5o 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 1900 1950 2000 2050 2100 2150 2200 2250 2300 2350 21(00 21*50 2500 200.82 206.11 211.39 216.68 2 2 1 .9 6 227.25 232.53 237.82 21*3.10 21*8.39 253.67 258.96 261*.21* 7 6 0 .9 7 7 6 .7 7 9 1 .6 8 0 7 .8 82l*.2 81*0.6 8 5 7 .7 873.7 8 90.8 9 0 7 .8 9 2 5 .1 91*1.8 9 6 0 .2 9 7 6 .3 9 9 5 .0 1011.1* 1 0 2 9 .8 101(6.8 1061*. 5 1 0 8 0 .9 1 1 0 0 .0 1000 1050 1100 1150 1200 1250 1300 1350 11*00 11(50 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2500 2550 2600 2650 2700 2750 2800 2850 2900 2950 3000 3050 3100 3150 3200 3250 3300 3350 31*00 31*50 3500 261* .21* 269.53 271*. 81 280.10 285.38 290.67 295.95 301 . 21* 306.52 311.81 317 .09 3 2 2 .3 6 327.65 3 32.95 338.23 31*3.52 3U8.80 351* .09 359.37 361*. 66 369.91* C a p a c ita n c e M .* x f X 10* *Coluron A g iv e s the t o t a l number o f u n its on th e primary standard c a p a c ito r th a t correspond to the number o f u n its covered on the p r e c is io n co n d en ser. 67 TABLE V I I I CALIBRATION DATA FOR THE H ELIC O ID GAGE H e lic o id Gage R ead ing P re ssu re mm. o f Hg H e lic o id Gage H eading P re s s u r e mm. o f Hg C a l i b r a t i o n a t 72.5°C C a l i b r a t i o n a t 1 1 5 .8°C 36 95 190 293 376 1*58 51*9 623 678 730 30 98 183 265 357 1*32 510 600 673 732 6 8 9 .5 6 3 0 .0 5 2 5 .9 1*33.5 3 5 3 .1 2 7 0 .0 183.0 1 0 7 .1 5 2 .8 < 1 .0 C a l i b r a t i o n a t 89.5°C 27 95 215 286 381 1*70 569 61*9 735 701*. 9 635.1* 51 6 .5 1*1*6 .1 353.2 2 6 5 .2 1 6 6 .8 8 7 .0 < 1 .0 698.8 630.5 51*3.5 1*6 3 .8 372.3 2 9 9 .9 2 2 0 . 1* 131*. 3 5 9 .0 < 1 .0 -C a lib ra tio n - a t 1 2 9 .2°C 21 165 239 31*0 1*31 513 585 658 727 699.6 551* .1 1*82.2 381.8 29 5 .0 211.0 11*0.7 7 0 .1 < 1 .0 C a l i b r a t i o n a t 1 0 1 . 8°C C a li b r a t i o n a t 11*1* ,1°C 19 82 168 271 370 l*5o 533 6oU 670 73h 19 102 170 278 352 1*1*3 533 621 679 725 7 1 1 .1 61*6.6 56 2 .7 1*59.1 3 6 2 .0 281.3 2 0 0 .0 1 2 9 .7 63.7 < 1 .0 7 0 1 .6 61 6 .0 51*9.1* 1*1*2 .8 367.7 280.0 1 8 8 .8 1 0 2 .6 1*6 .8 < 1 .0 68 Helicoid Gage Reading 600 UOO 200 O O 200 UOO 600 P re s s u re mm. o f Hg F ig u re 13 T y p ic a l c a l i b r a t i o n cu rv e f o r th e H e lic o id p r e s s u r e g a g e . C a l i b r a t i o n a t 1 1 5 .8°C. 69 TABLfi IX CALIBRATION DATA FOR DIELECTRIC CELL I I P re ssu re mm. o f Hg C ondenser R ead in g C a p a c ita n c e C a l i b r a t i o n a t 7 2 .5 °" 1 5 9 .0 1 6 6 .5 1 6 9 .0 1 7 1 .3 1 7 3 .7 1 7 6 .8 1 8 0 .2 1 8 3 .1 7 8 5 .0 5 3 5 .3 1+61*.5 3 9 1 .2 3 0 7 .1 2 0 8 .0 9 9 .0 < 1 .0 0 .2 8 7 0 .3 2 0 0 .3 3 1 0.31*1 0.352 0 .3 6 6 0 .3 8 1 0.391* C a l i b r a t i o n a t 89.5°C 7 8 7 .0 6 8 3 .6 586.1+ 1+78.8 3 9 8 .8 2 9 7 .3 1 9 6 .7 9 1 .8 < 1 .0 1 6 2 .6 1 6 5 .5 1 6 8 .6 1 7 1 .5 171* .0 177.1* 1 8 0 .0 1 8 3 .3 1 8 5 .9 0 .3 0 3 0 .3 1 5 0 .3 2 9 0.31*2 0 .3 5 3 0 .3 6 9 0 .3 8 0 0 .3 9 5 0.1*06 7 8 1 .8 6 7 3 .5 5 5 0 .3 1+61*. 0 3 6 1 .2 2 7 0 .1 1 8 5 .0 9 9 .5 < 1 .0 1 6 1 .5 161*. 8 168 1 1 7 0 .8 171+.0 1 7 6 .9 1 7 9 .2 1 8 1 .8 181*. 2 0 .2 9 8 0 .3 1 2 0 .3 2 7 0 .3 3 9 0 .3 5 3 0 .3 6 6 0 .3 7 7 0 .3 8 8 0 .3 9 9 C a l i b r a t i o n a t 1 0 1 .9°C 7 7 9 .8 702.1* 699.1* 1+97.2 3 9 6 .1 3 0 2 .7 1 9 9 .6 105.1* < 1 .0 287.2 2 8 9 .8 2 9 2 .8 2 9 6 .0 2 9 9 .1 3 0 2 .1 3 0 5 .2 3 0 8 .2 311.1* 0.81*9 0 .8 5 9 0 .8 7 2 0 .8 8 5 0 .8 9 8 0 .9 1 0 0 .9 2 3 0 .9 3 5 0.91*8 P r e s stir© mm. o f Hg C ondenser R eading C a p a c ita n c e /V * * C a li b r a t i o n a t 1 1 5 ,7°C 792.2 6 9 5 .8 596.1+ 1*35.0 31*7.8 21*7.7 1 3 6 .0 < 1 .0 1 8 6 .3 1 8 9 .6 1 9 2 .3 196.7 1 9 8 .9 2 0 1 .7 201*. 9 2 0 8 .5 0.1*09 0.1*23 0.1*35 0.1*55 0.1*61* 0.1*77 0.1*91 0 .5 0 8 C a l i b r a t i o n a t 12 8 . 8°C 7 8 3 .9 7 0 2 .8 603.5 1*72.6 3 8 5 .1 2 8 9 .8 1 85.7 8 6 .0 < 1 .0 11*9.0 151.2 153.7 1 5 7 .1 159.1* 1 6 2 .1 161*.3 1 6 7 .0 1 6 8 .9 0.21*0 0 .2 5 1 0 .2 6 1 0 .2 7 9 0 .2 8 8 0 .3 0 1 0 .3 1 1 0 .3 2 2 0 .3 3 0 C a l i b r a t i o n a t 11+1+.1°C 7 8 9 .8 7 0 0 .7 5 6 9 .5 1*81.0 3 8 6 .6 2 9 9 .3 2 05.8 98.1* < 1 .0 1 8 2 .7 181*. 8 1 8 7 .5 1 9 0 .0 1 9 2 .5 191+.6 1 9 7 .0 1 9 9 .9 2 0 2 .6 0 .3 9 2 0.1*01 0.1*11* 0.1*25 0 . 1*36 0 .1*1*5 0.1*56 0 . 1*69 0.1*81 70 Capacitance, jutp f 500 U20 0 200 U00 600 800 P r e s s u r e , mm. o f Hg F ig u re l i i . T y p ic a l p l o t o f c e l l c a l i b r a t i o n d a t a . C a l i b r a t i o n o f C e ll I I a t 1 1 5 .7°C . 71 TABLE X VALUES OF A C FOR CARBON DIOXIDE FROM DATA IN TABLE IX T em p eratu re Oq * C o rre c te d P re s s u r e mm. o f Hg C 7 2 .5 895.1 0 .1 2 2 8 9 .5 91*0.1 0 .1 2 3 8 9 .5 9U0.1 0 .1 2 3 1 0 1 .9 9 7 1 .2 0.1 2 3 1 1 5 .7 1 0 0 7 .0 0 .1 2 3 1 2 8 .8 101*0.9 0 .1 2 2 ll*U .l 1072.8 0.12U A 0 Average * 0 .1 2 3 P r e s s u r e e x e r te d a t t°C by th e m o la r volume o f c arb o n d io x id e a t 20°C . 72 0 .9 0 0 0.800 0 .700 0.600 Capacitance ft O.J4OO 0.200 0.100 O 200 Uoo 600 800 P r e s s u r e , ram. o f Hg F ig u re 1 5 . T y p ic a l p l o t o f c a p a c ita n c e v e rs u s p r e s s u r e f o r brom ine p e n ta f lu o r i d e a t 1 1 5 .8°C . 73 TABLE X I VALUES OF A C FOE BROMINE PENTAFLUORIDE FROM THE DATA IN TABLE V I T e m p e r a tu r e °c ( 0-1 7 2 .5 A C mm? atm o f B rF e ) A verage ^ C y .y .£ 0.81*1* 0.81*2 0.81*3 8 9 .5 0 .7 7 5 0 .7 7 7 0.7 7 7 0 .7 7 7 1 0 1 .9 0 .7 3 5 0 .7 3 8 0 .7 3 9 0 .7 3 7 1 1 5 .8 0 .6 9 1 0 .6 9 2 0 .6 9 0 0 .6 9 1 1 2 9 .2 0.651* 0 .6 5 6 0 .6 5 5 11*1* .1 0.6 1 3 0 .6 1 5 0.611* 0 .5 8 6 0 .5 8 6 0.581* 1 5 7 .7 0 .5 8 0 7h tt o H CA On CO • CM K o W Q <}> H O .F S Ph \o CO XA C*» • CM • On XA XA -=J On vO o a i—1 vfc NO • CM XA • CM vO vO SB ~CT ♦ CM On CM CM CM CA cA O XA XA XA XA Xa CM XA xa On t*— On CM On On CM O CM XA CM CA o p-. < S3 t) § r— CJD CM On CM O ca rH CA CM O co CA On CO CA co ~=t CM C*— •» •* •> •i On NO CA •» O P C O Cm § C— ca to §3 M H * o Sc M a t*— fc! M rH • * -'n CM + VJ Vl> a rH CM rH rH rH CO A N rH rH 7h eC gPif '— ' f-. T3 <0 O O Phi O CM CA NO 9 § -= t CM CO XA XA CM XA XA O CO H On XA ca CO § ~a ?a ~=t Vil 1 +i O • o t* CA r• O H - On NO • O XA XA NO • ■a NO CO xa o IS H 9 e ® O a. o | o o NO • XA -= t CA NO • CM NO fA On C— CA OO CO CA XA XA • On oo CO • co« CM A- • On • H XA S 3 co -z t • CM CM r- O s a 3 CM • On CM rH -= t ;3 XA rH E-» 75 68 6h o o & 60 52 2. U 2.6 3 .0 2.8 T°K 3 .2 3.U 103 F ig u r e 1 6 . M olar p o l a r i z a t i o n v e rsu s £he r e c i p r o c a l o f th e .a b s o l u te te m p e ra tu re f o r brom ine p e n t a f l u o r i d e . 76 C h lo r in e T r i f l u o r id e D a ta . The d a ta f o r p l o t t i n g th e c a p a c ita n c e -v e r s u s -p r e s s u r e c u r v e s f o r c h lo r in e tr iflu o r id e a r e p r e s e n t e d i n T a b le X I I I . c a lib r a tio n o f th e c e l l v a lu e o f and H e l i c o i d A C a t e a c h te m p e r a tu r e i s d ie le c tr ic The d a ta f o r th e gage a r e n o t sh ow n . The a v e r a g e g i v e n i n T a b l e X IV , a l o n g w i t h t h e c o n s t a n t a t e a c h t e m p e r a t u r e a n d t h e m o la r p o l a r i z a t i o n . T h e m o la r v o lu m e o f t h e c h l o r i n e t r i f l u o r i d e w as o b t a in e d u s i n g t h e B e r th e lo t e q u a t io n - o f - s t a t e , VM P L PqT 128 PrjT and t h e c r i t i c a l c o n s t a n t s e s tim a t e d D i p o l e m o m e n t. th e J by G r l s a r d , B e r n h a r d t , an d O l i v e r (5 3 ) T h e p l o t o f m o la r p o l a r i z a t i o n a b s o lu te te m p e r a tu r e i s s tr a ig h t lin e T2 17. sh o w n i n F i g u r e a g a in s t th e r e c ip r o c a l o f The s l o p e o f t h e a s d e t e r m in e d b y t h e l e a s t - s q u a r e s m e th o d ( 3 ,3 6 U ) corres­ p o n d s t o v a l u e f o r t h e d i p o l e m om ent o f yk The c a l c u l a t i o n a s lig h tly - o .7U d o f t h e d i p o l e m om ent u s i n g t h e m o la r r e f r a c t i o n d iff e r e n t v a lu e . M a li k t io n o f c h lo r in e t r if lu o r id e C55) h a s d e t e r m in e d t h e m o la r r e f r a c ­ fr o m r e f r a c t i v e g a s , and g i v e s a v a lu e o f R * gave 1 0 .3 ■* 0 . 5 . i n d e x m e a s u r e m e n ts o n t h e S u b s t it u t in g t h i s v a lu e t h e m o la r p o l a r i z a t i o n a t e a c h te m p e r a tu r e i n t o E q u a tio n r e s u l t s sh o w n i n T a b le XV. and 17 g i v e s t h e T he a v e r a g e v a l u e o f t h e m om ent o b t a i n e d 77 TABLE X IH DIELECTRIC CONSTANT DATA FOR CHLORINE TRIFLUORIDE P re ssu re iren. o f Hg C a p a c ita n c e Me a su rem e n ts a t 1*6.2°C 733 651 596 533 1*55 391* 315 202 87 <1 0 .3 3 0 0 .3 7 0 0 .3 9 9 0.1*31 0.1*69 0.1*99 0 .5 3 7 0 .5 9 2 0.61*8 0 .6 9 6 736 662 602 521* 1*58 393 295 191* 85 <1 0 .3 1 5 0 .3 5 3 0 .3 8 2 0 .1,22 0.1*51* 0 . 1,86 0 .5 3 2 0 .5 8 3 0.631* 0 .6 7 9 M easurem ents a t 78.7°C 732 621 501* 1*1*8 1*01 311* 205 91* <1 0 .8 3 1 0 .8 7 9 0 .9 2 7 0 .9 5 1 0 .9 7 6 1 .0 0 6 1.051* 1 .0 9 9 1.11*3 731 6i*i* 51*0 1*89 1*28 31*3 21*7 11*9 81 <1 0 .8 2 7 0 .8 6 5 0 .9 1 1 0 .9 3 5 0 .9 5 6 0 .9 9 5 1 .0 3 6 1 .0 7 8 1 .1 0 9 1.11*7 P re s s u r e ram. o f Hg C a p a c ita n c e Me a su rem en ts a t 1 0 2 .2°C 755 683 608 515 2±06 299 201 92 <1 0 . 51,0 0 .5 6 5 0 .5 9 2 0 .6 2 9 0 .6 7 1 0 .7 0 9 0 . 71,6 0 .7 9 8 0.81*9 721 661 609 518 h2h 310 199 83 <1 0 .5 2 7 0 .5 5 3 0 .5 7 6 0 .6 1 6 0.651* 0 .7 0 0 0 . 71,6 0 .8 0 1 0.81*7 729 656 553 U50 3U9 250 IJ48 <1 0 .5 2 2 0.55U 0 .6 0 1 0.61*1, 0 .6 9 6 0 .7 2 6 0 .7 5 2 0 .8 5 0 O M easurem ents a t 1U0.8 C 721* 678 621 563 1*96 1£3 329 231 101* <1 O.ijOl O.I4I 8 0.1437 O.U55 0 .I478 0 .U98 0.53U 0 .5 6 6 0 .6 1 0 0 .6 5 0 78 TABLE XIV MOLAR POLARIZATION CALCULATIONS FOR CHLORINE TRIFLUORIDE CD 3 K H1 AC * MMf >— * T e m p e ra tu re , °K M olar Volume, cc /m ole P M cc/m o le i x lo 3 T°K 3 1 9 .3 0 .372 2825 2 5 ,7 5 6 2U.2 3.132 3 5 1 .8 0 .3 2 8 2U90 2 8 ,k 8 8 2 3 .6 2.81*2 3 7 5 .8 0 .3 0 2 2293 30,512 2 3 .3 2 .6 6 1 U13.3 0 .2 5 k 1929 33,707 2 1 .7 2.1*16 * R e p la c e a b le c a p a c i ta n c e , CQ • 132 MM f. 26 CD i— 1 O u o 20 18 2.L0 2.60 2. 80 3 .2 0 ho * i°3 T K F ig u re 1 7 . M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r c h lo r in e t r i f l u o r i d e . 79 i n t h i s m anner i s J* * T h is D. a g r e e s w i t h t h e v a l u e o b t a i n e d fr o m t h e p l o t o f t h e m o la r p o l a r i ­ z a tio n v e r su s th e r e c ip r o c a l o f th e a c c u r a c y o f t h e m e a su r e m e n ts. a b s o lu t e te m p e r a tu r e w it h in th e (S e e D is c u s s io n o f E rro rs) TABLE XV DIPOLE MOMENT OF CHLORINE TRIFLUORIDE CALCULATED U SIN G THE MOLAR REFRACTION D i p o l e M om ent D T e m p e r a tu r e °K 3 1 9 .3 0 .8 3 3 5 1 .8 0 .8 6 3 7 5 .8 0 .8 7 U13.3 0 .8 5 I o d in e F e n t a flu o r id e D a ta . The d i e l e c t r i c th e r e s u lt s o f t h e v a r io u s p l o t s T a b le X V II. d ie le c tr ic range. c o n s ta n t d a ta a re p r e se n te d B ecau se o f th e i n T a b le X V I y an d and c a l c u l a t i o n s a r e s u m m a r iz e d i n h ig h b o i l i n g p o in t o f t h i s com p ou n d , t h e c o n s t a n t c o u ld n o t be m ea su red o v e r a la r g e te m p e r a tu r e T h erefo re i t w as n o t p o s s i b l e t o p l o t o f m o la r p o l a r i z a t i o n te m p e r a tu r e . o b ta in s u f f i c i e n t d a ta f o r v e r su s th e r e c ip r o c a l o f th e a b s o lu te a TABLE 171 DIELECTRIC CONSTANT DATA FOR IODINE PENTAFLUORIDE P re ssu re iran. o f Hg C a p a c ita n c e JU/Af M easurem ents a t 1 1 9 .6°C 239 1U6 59 <1 0.81*0 0 .9 6 8 1.071* 1 .1 5 2 21*6 216 188 168 1 1*2 113 81 63 <1 o .8 5 o 0 .8 9 1 0.927 0 .9 5 5 0 .9 9 2 1 .0 3 1 1 .0 7 3 1 .0 9 5 1 .1 7 3 0 .7 6 3 0 .8 2 5 0 .8 7 1 0 .9 0 7 0.91*7 0.971* 1 .0 2 0 1 .0 5 1 1 .0 9 8 1 .1 7 7 Q M easurem ents a t 1 3 5 .0 C 293 2^2 220 195 170 11*7 116 96 60 <1 253 221 197 171 lh 7 118 90 53 19 <1 0 .7 3 2 0 .7 7 3 0 .8 0 6 0.81*1 0 .8 6 8 0 .9 0 6 0.91*2 0 .9 8 3 1 .0 2 6 1 .0 5 2 P re ssu re iran. o f Hg C a p a c ita n c e fx y£ M easurem ents a t 135°C ( c o n t 'd ) 221 196 171* 151 123 lOii 65 35 <1 0 .7 5 6 0 .7 9 0 0 .8 1 7 0.81*9 0.881* 0 .9 0 8 0 .9 5 6 0.992 1.01*1 231 210 161 151 122 92 57 0 .7 5 3 0.781* 0.827 0 .6 6 6 0 .9 1 0 0 . 91*8 0.992 a Cl M easurem ents a t 150.1* C 205 177 liUi 112 82 52 16 <1 0 .8 7 5 0 .9 1 3 0.91*9 0 .9 9 1 1 .0 2 6 I.O 63 1.1 0 3 1 .1 0 7 218 19ii 171 11*7 118 90 61 39 <1 0 .8 3 7 0 .8 6 3 0 .8 9 1 0 .9 1 7 0 .9 5 3 0 .9 8 7 1 .0 2 1 1.01*6 1.107 81 TABLE X V I (CONTINUED) P re ssu re mm. o f Hg C a p a c ita n c e Me asu ro m en ts a t 1 5 0 .1*°C 210 191 171 llil 113 92 58 3k <1 P re s s u r e mm. o f Hg C a p a c ita n c e M easurem ents a t 172 ,9°C (c o n tin u e d ) 0.799 0 .8 2 5 0.81,5 0 .8 8 0 0 .9 1 6 0.91*3 0 .9 7 5 1 .0 1 1 1 .0 6 6 205 168 139 116 88 60 38 17 <1 1.01*3 1.000 1 .1 1 1 1 .1 3 7 1.167 1.198 1 .2 2 1 1 .21*3 1 .2 6 1 198 173 1U9 111 82 53 31 lii <1 1 .0 3 3 1 .0 5 9 1.081, 1.121* 1 .1 5 5 1 .1 6 5 1 .2 0 8 1 .2 2 6 1.21,0 Me asu rem e n ts s t 1 7 2 ,9°C hZk 36U 283 213 157 llii 73 55 <1 0.81,6 0 .9 1 7 1 .0 0 1 1 .0 6 8 1 .1 2 5 1 .1 6 9 1 .2 1 3 1.231* 1 .2 9 2 209 180 155 131 98 6U 37 15 <1 1.061, 1 .0 9 3 1 .1 1 6 1 .1 2 9 1 .1 7 5 1 .2 0 8 1 .2 3 8 1 .2 5 7 1 .2 7 3 b2 -c f CM • CM -G f CM • CM XA CM • CM CA CM • CM C— co c*•X OO XA rH Os •V o CA _=f Os rH «% O CA EH « ^P M I P4 0 •N & I Le I3 Pi Q s « w 525 gH I— I fSfl n ° < • _ * * sO * r~ Os rA • -3 Os o o CM • CM Os Os sO QO o o Q) O §M 2 «H O ga ® rH O CO o 3 £h § s o © O > s < • O o 3 CM *» CM CA XA O XA h rH PQ •8 Q> <0 8 GO o rH Os rH 1 nj •=2 M Q s S8 GO CA Os C— XA CA rH C^* * u w“ * • CL, E Q> Eh ■a « 5( 5 « O i—1 rH O* rH o -G* Os * O XA CO GO • O CM Os c*• O C*— • CM Os CA rH * GO o -G j XA • CA CM -= f O• sO 3 83 D ip o le Moment. M alik 155) h a s o b ta in e d a v a lu e o f 1 9 .2 cc./™ 0!® f o r th e m o la r r e f r a c t i o n R o f io d in e p e n t a f l u o r i d e . T h is v a lu e was u sed t o o b t a i n t h e v a lu e o f B i n E q u a tio n 17 a t e ac h te m p e r a tu re , from w hich t h e d ip o le moment was c a l c u l a t e d . The d e t a i l s o f th e c a l c u l a t i o n s a r e g iv e n i n th e l a s t t h r e e colum s o f T ab le XVTI. The e x c e l l e n t a g re e ­ m ent b e tw ee n th e s e v a lu e s i n d i c a t e s t h e p r e c i s i o n ld iic h i s p o s s ib l e i n m e a su rin g compounds w hich p o s s e s s a h ig h d ip o le moment. The a v erag e v a lu e f o r th e d ip o le moment o f io d in e p e n ta f l u o r i d e i s JA » 2.21* D . Bromine T r i f l u o r i d e D a ta . The d i e l e c t r i c c o n s ta n t d a ta f o r brom ine t r i f l u o r i d e a re p r e s e n te d i n T a b le XVXII. T h is was th e h i g h e s t b o i l i n g compound m e a su re d , and t h e r e f o r e a v e ry s m a ll te m p e ra tu re ra n g e was a v a i la b l e o v e r which th e d i e l e c t r i c c o n s ta n t d a t a c o u ld b e o b ta in e d . The c a l c u l a t i o n s a re sum m arised i n T a b le XIX. D ip o le m oment. The d ip o le moment was c a l c u l a t e d u s in g th e v a lu e o f 1 2 .9 cc ./m o le f o r th e m o la r r e f r a c t i o n o b ta in e d by M alik ^ 5 5 ) . The a v e ra g e v a lu e o f th e d ip o le moment a t th r e e d i f f e r e n t te m p e ra tu re s i s JL4 = 1 .3 3 D. TABLE X V I I I DIELECTRIC CONSTANT DATA FOR BROMINE TRIFLUORIDE P re ssu re mm« o f Hg C a p a c ita n c e P re ssu re mm. o f Hg C a p a c ita n c e M easurem ents a t lii2 .U°C Me a s u r em ents a t 1 5 1 .6°C 197 182 151 125 89 59 21 <1 0.2U7 0 .2 5 2 0 .2 7 0 0 .2 8 0 0 .3 0 0 0 .3 1 5 0 .3 3 2 0.3l*li 121 73 36 <1 0 .6 8 3 0 .7 0 5 0 .723 0.7U0 198 171 1U3 115 87 57 29 <1 0 .2 3 6 0 .2 8 9 0 .2 5 6 0 .2 8 3 0 .2 9 9 0 .3 1 5 0 .3 3 2 0.3U8 296 2U7 196 H18 108 61 20 <1 0 .5 6 8 0 .5 9 1 0 .6 1 5 0 .6 3 9 0 .6 5 6 0 .6 7 9 0 .6 9 8 0 .7 0 7 215 191 162 131 105 80 56 23 <1 0 .2 5 9 0 .2 7 3 0 .2 8 5 O .3O8 0 .3 1 9 0 .3 3 0 0 .3 8 3 0 .3 6 3 0 .3 7 3 A Me asurem fehts a t 1 5 1 .6 C 290 227 183 137 90 h2 <1 0 .6 3 0 0 .6 6 1 0 .6 7 9 0 .7 0 0 0 .7 2 2 0.71U* 0 .7 6 3 278 220 163 0 .6 0 9 0 .6 3 6 O.663 M easurem ents a t 1 7 5 .1 C 290 250 216 158 121 78 29 <1 0 .592 0 .6 1 0 0 .6 2 5 0 .6 h9 0 .6 6 1 0 .6 8 0 0 .7 0 6 0 .7 1 8 302 265 221 186 118 81 29 <1 0 .5 7 1 0 .5 8 8 0 .6 0 7 0.622 O.651 0 .667 0 .6 9 0 0 .7 0 2 310 262 218 171 123 79 27 <1 0 .5 3 6 0 .5 5 3 0 .5 7 9 0 .5 9 7 0 .6 1 8 0 .6 3 7 0 .6 6 0 0 .6 7 2 85 Q o -d • 1—1 On CM • rH O CO r -i 6-i "3 Q t as tA CO -d CO CO C\J CO _d c\l O O O- vO CO •k *» *( * p CD rH O ^E n h 3i3 P vO CM — d co co o o I 3 « CD rH X 9 co O ^ E md -d co 3 c>\ -d co o On nO CO o Cl> S -P ♦H §* O u> 3 Q> rH « OO -d C"*— CO rH I On CO rH CO -d NO On CM \U •3 CD S rH Qh <3 * o <3 CH * NO ~d 3 i / \ co O n CM CO o xr\ E» EorH 1A 3 CM -d co -d - d ~ d CNJ 86 F lu o ro c a rb o n D e r iv a tiv e s 1 ,1 ,1 ^2 ,2 ,3 ,3 -h e p ta flu o r o p r o p a n e D a ta . The d i e l e c t r i c c o n s ta n t d a ta a re p r e s e n te d i n T a b le XX. The c e l l u se d f o r th e f lu o r o c a rb o n d e r i v a t i v e work ( C e ll i ) had a much l a r g e r r e p l a c e a b l e c a p a c ita n c e th a n C e ll X I, t h e r e f o r e l a r g e r c a p a c ita n c e ch an g es were o b se rv e d upon p l a c in g a gas betw een th e p l a t e s * c r e a s e d th e p r e c i s i o n o f th e m e a su re m e n ts. T h is i n ­ The c a l c u l a t i o n s o f th e m o la r p o l a r i s a t i o n a r e sum m arised i n T ab le XXX, D ip o le moment. The p l o t o f m o la r p o l a r i s a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re i s shown i n F ig u re 1 9 . The s lo p e o f th e l i n e B o b ta in e d by th e l e a s t - s q u a r e s method i s e q u a l t o 15 ,9 6 0 and th e d ip o le moment c a l c u l a t e d from t h i s i s y = 1 .6 2 D. P e r f lu o ro te tr a m e th y le n e Oxide D a ta . The d i e l e c t r i c c o n s ta n t d a ta a re p r e s e n te d i n T ab le X X II, and th e c a l c u l a t i o n s a r e sum m arised i n T ab le X X III. D ip o le moment . o f th e a b s o lu te The p l o t o f m o la r p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l te m p e ra tu re i s shown i n F ig u re 1 9 . l i n e B d e te rm in e d by a l e a s t - s q u a r e s method i s 1931, and th e d ip o le moment c a l c u l a t e d from t h i s i s y The s lo p e o f th e = 0 .5 6 D. TABLE XX DIELECTRIC CONSTANT DATA FOR 1 , 1 , 1 , 2 , 2 ,3 ,3-HEPTAFLUOROPROPANE ( n - C ^ H ) P re ssu re ram. o f Hg C a p a c ita n c e fJLfif P re ssu re mm. o f Hg C a p a c ita n c e Me asurem e n t s a t 26.7°C Me asu rem en ts a t 1*8.1*°C 7 8 8 .0 TOh.O 6 0 7 .3 5 0 7 .3 391*. 7 2 9 8 .0 1 9 5 .8 1 0 0 .0 0 .5 787.2 701*.7 5 9 9 .0 1*91.1 3 9 3 .6 2 9 7 .9 2 0 1 .2 lOU.S 0 .1 0 .2 6 1 0 .586 0.951* 1 .3 3 2 1 .7 6 3 2 .3 3 2 2.502 2 .8 6 5 3 .2 1 6 He a su re m e n ts a t 3U.2°C 7 8 0 .3 6 9 0 .8 ' 600.1* 1*98.6 3 9 1 .5 2 9 3 .2 1 9 8 .lt 1 0 6 .3 0 .2 0 .5 1 0 0 . 8i4.lt 1 .1 6 5 1 .5 U 1 .9 0 8 2.2 7 9 2.621* 2 .9 5 1 3 .3 0 9 0 .2 5 7 0 . 51*8 0 . 901* 1 .2 6 0 1 .5 8 1 1 .8 9 8 2 .2 0 9 2.527 2.861* M easurem ents a t 61.1°C 7 9 2 .1 6 9 6 .9 6 0 3 .1* 1*97.2 390.0 293.0 1 9 9 .2 1 0 0 . i* 0 .2 0.1*95 0 .7 9 7 1.0 8 5 1.1*15 1 .7 5 1 2.01*9 2.31*3 2.653 2.91*9 M easurem ents a t 1*1.0 C M easurem ents a t 6 9 .1*°C 7 8 5 .0 702.7 605.8 5 0 2 .3 39lt.O 3 0 3 .5 19it .0 9 8 .3 0 .1 7 9 0 .9 69 9 .9 599.8 503.2 398.2 2 9 5 .3 1 9 9 .5 9 7 .2 0 .1 0.1*53 0.71*5 1.081* 1.1*1*8 1 .8 2 6 2 .1 1 6 2.512 2 81*1* 3 .1 6 3 0.1*97 0 .7 7 6 1.071 1.357 1.677 1.9 7 9 2.2 5 6 2.561 2.8 3 8 88 TABLE XX (CONTINUED) P re ssu re mm. o f Hg C a p a c ita n c e Me a su rem e n ts a t 79.3°C 7 9 1 .9 70U .0 6 0 1 .6 1*87.8 1*0 3 .0 2 9 9 .0 1 8 9 .0 1 0 0 .5 0 .2 0 .5 0 8 0 .7 6 2 1 .0 5 2 1 .3 6 8 1 .6 1 6 1.901* 2 .2 0 6 2.1*59 2 .7 3 8 M easurem ents a t 89.8°C 7 8 0 .3 6 9 9 .2 5 7 6 .7 1*91.6 3 9 0 .5 2 7 6 .7 2 0 3 .2 1 0 9 .0 0 .2 1 .0 5 6 1 .2 1 0 1.1*1*8 1 .6 1 8 1 .8 1 1 2.027 2 .1 6 3 2.31*1* 2 .5 6 7 P re s s u re mm. o f Hg C a p a c ita n c e MM* Me asurem e n t s a t 1 0 9 .0°C 7 89.7 701*. 5 6 0 0 .5 1*8 6 .8 381*. 5 292 .1 2 0 1 .8 102.1* 0 .2 0 .5 6 8 0 .7 8 0 1 .0 2 8 1 .3 0 9 1 .5 6 9 1 .7 9 5 2.015 2.25U 2.1*99 M easurem ents a t 99.8°C 781*.1 6 9 8 .1 5 9 8 .8 1*83.1 3 9 8 .7 3 0 1 .3 1 85.2 1 0 2 .2 0 .2 0 .5 2 2 0 . 71*6 1.000 1 .2 9 3 1 .5 1 6 1.767 2 .0 5 9 2.267 2 .5 2 0 89 TABLE X X I MOLAR POLARIZATION CALCULATIONS FOR 1 ,1 ,1 ,2 ,2 ,3 , 3-HEPTAFLUOROPROPANE T em p era tu re °K A c* yUUf 2 .860 2.71*5 2.61*0 2 .5 0 0 2.361* 2.251* 2 .1 3 6 2.032 1 . 91*0 1 .8 6 0 2 9 9 .8 3 0 7 .3 3X1* .1 3 2 1 .5 331* .2 3U2.5 3 5 2 .5 3 6 2 .3 3 7 2 .9 3 8 2 .1 (€ - l ) x 10 6 8101, 7778 7U81 7081* 6699 6387 6053 5758 51*97 5271 * R e p la c e a b le c a p a c i ta n c e , CQ = 353 Vm c c/fao le PM ce/frtole 21*,611* 25,229 25,788 2 6 ,3 9 5 2 7 ,1*38 28,119 28,932 29,71*5 3 0 ,6 1 5 31,370 6 6 .3 65.2 61* .1 6 2.2 6 1 .1 59.7 5 8 .3 5 7 .0 5 6 .0 5 5 .0 jum ? i n x 103 T°K 3 .3 3 6 3.25U 3.18L 3 .1 1 0 2.992 2 .9 2 0 2.838 2 .7 6 0 2.682 2 .6 1 7 . 66 H O o • o 3 .0 T°K F ig u r e 1 8 . M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re f o r 1 ,1 ,1 ,2 ,2 ,3 ,3 - h e p t a f l u o r o p r o p a n e . 90 TABLE X X II DIELECTRIC CONSTANT DATA FOR PERFLUOROTETRAMETHYLENE OXIDE ( c y c lic - ( C F a ) 40) P re ssu re mm. o f Hg C a p a c ita n c e V tfkf Me a su re m e n ts a t 26.1°C 7 8 l .it 7 2 0 .8 62t2.0 5 5 1 .0 1*56.1 3 7 2 .2 2 8 0 .8 193*3 1 2 1 .2 1*5.6 6 .7 1.010 1 .1 2 5 1 .2 7 0 1.U 39 1.63U 1 .7 8 7 1.951t 2 .1 1 0 2.2itO 2 .3 7 8 2 . it55 P re s s u r e mm. o f Hg C a p a c ita n c e JA.>*f M easur erne n t s a t 56.0°C 7 8 3 .it 697.0 591.3 5 2 1 .1 2 3 6 .5 3 6 8 .5 2 8 7 .2 2 07.2 1 28.7 5 8 .1 0 .6 1.382 l.5 ii0 1 .7 2 1 1 .8 3 it 1 .9 7 6 2 .0 8 9 2 .2 2 1 2 .350 2 .I18O 2 .6 0 0 2 .6 9 3 M easurem ents a t 36.9°C M easurem ents a t 66.7°C 7 9 0 .8 7 1 2 .1 6U6.5 5 8 1 .1 5 ll.lt UU7.8 3 6 9 .6 2 9 0 .0 206.it 1 2 9 .3 6it.2 0 .5 7 9 2 .8 725.0 657.0 5 7 3 .5 it92.7 it07.0 331.it 2 2 3 .1 1 6 3 .0 8ti.8 0 .7 0 .7 0 7 0 .8 9 5 1 .0 1 7 1.13U 1 .2 6 0 1 .3 7 6 1 .5 2 2 1 .6 7 1 1 .8 1 8 1 .9 5 3 2 .0 6 8 2 .1 7 9 M easurem ents a t itit.7°C 7 8 3 .0 7 1 7 .3 6 6 2 .3 5 9 5 .5 5 1 5 .8 it26.7 3 5 2 .3 2 6 5 .3 17 it.it 8 1 .0 0 .7 1 .1 3 7 1.25U 1.35U l.it7 3 1 .6 2 0 1 .7 7 3 1 .9 0 it 2.0 5 3 2 .2 0 6 2.36it 2.U97 1.U23 1 .5 i tl 1.657 1 .7 8 8 1 .9 1 9 2.0it8 2 .1 7 6 2.311i 2.itit)t 2 .5 6 9 2 .7 0 6 M easurem ents a t 7it.6°C 7 8 7 .1 7 1 7 .5 6U9.0 5 7 6 .0 501.3 U12.8 325.0 23 5 .2 lit9 .it 7 0 .3 0 .3 0 .6 2 9 0 .7 3 8 0 .8 it6 0 .9 5 9 1 .0 7 3 1.207 1.3it7 1.U89 1 .6 2 7 1.7ltit 1.853 91 TABLE X X II (CONTINUED) P re ssu re o f Hg C a p a c ita n c e mm. P ressu re mm. o f Hg Me asu rem e n ts a t 82.9°C M e a s u r e m e n ts 7 8 9 .8 716.7 6 5 2 .0 5 8 6 .3 5 0 8 .8 1*30.9 3 5 8 .1 2 6 8 .9 1 9 2 .0 1 1 8 .9 5 6 .2 0 .3 7 8 7 .8 7 1 0 .7 61*5.0 566.7 1*92.0 1*1*0.1* 372.1 3 H .0 31*1*. 1* 1 60.7 7 2 .5 0.1* 0 .6 9 3 0 .8 0 9 0 .9 0 5 1 .0 0 5 1 .1 1 8 1.231* 1.3U2 1.1*72 1 .5 9 8 1 .7 0 8 1.800 1.881* Me a su re m e n ts a t 93.2°C 781* .9 7 1 1 .1 61*5.2 5 7 2 .3 5 0 8 .5 1*21* .1 31*3.5 2 6 6 .6 191*.8 1 1 9 .5 1*9.7 0 .5 0 .7 0 5 0.811* 0 .9 1 0 1.011* 1 .107 1.228 1.31*6 1.1*59 1 .5 6 6 1.677 1 .7 7 3 1.81*7 C a p a c ita n c e f a t 1 0 1 .8°C 0 .7 6 9 0 .8 8 0 0 .9 7 2 1 .0 8 6 1 .1 9 0 1 .2 6 1 1 .3 6 0 1 . 1*50 1.562 1 .6 6 7 1.781* 1 .8 0 9 Me asu rem en ts a t 111.1°C 7 8 8 .7 7 0 1 .8 61*2.8 5 6 9 .6 1*83.5 3 9 7 .0 3 1 0 .6 221* .5 11*9.8 7 6 .8 0 .2 0 .7 9 3 0 .9 1 6 1.001* 1 .0 9 7 1 .2 1 6 1 .3 3 7 ’ 1.1*59 1 .5 7 8 1 .6 8 1 1 .7 8 0 1.881* 92 TABLE X X II I MOLAR POLARIZATION CALCULATIONS FOR PEHFLUORQMETHYLENE OXIDE Tem perature °K 299.2 310 .1 317.2 32 9.1 3 3 9 .8 3V7.7 3 5 6 .1 3 6 6 .3 375. h 38U.2 yuyuf 1.1+13 1.362 1 .3 1 3 1 .2 5 5 1 .2 1 9 1 .1 8 1 1.155 1 .1 0 a 1.088 1 .0 5 5 (€ - l ) x 106 1+039 389U 3753 3588 31485 3385 3273 3167 3110 3016 o c /m o le ^ cc/rnole i 3 T°KX ^ 25,561+ 25 ,551 26,052 27,019 27,898 28,556 29,236 30,073 30,820 31.5U3 33.0 32 .9 3 2 .5 32 .3 32.1+ 32.2 31 .9 31.8 31.9 3 1 .6 3.35-2 3.2 2 6 3.15 3 3.0 3 9 2.91+3 2 .8 7 6 2.80 8 2.730 2 .661+ 2.603 * R e p la c e a b le c a p a c ita n c e C0 * 350 m m f . 3h 32 30 2 3 .2 F ig u r e 1 9 . Molar p o l a r iz a t i o n v e r s u s th e r e c ip r o c a l o f th e a b s o lu te tem p era tu re f o r p e r flu o r o te tr a m e tb y le n e o x id e . 93 P e r f l u o r o e t h y l E th e r D a ta . The d i e l e c t r i c c o n s ta n t d a ta a re p r e s e n te d i n T ab le XXIV, and th e c a l c u l a t i o n o f th e m o la r p o l a r i z a t i o n a t each te m p e ra tu re i s sum m arized i n T a b le XXV. D ip o le m oment. The p l o t o f th e m olar p o l a r i z a t i o n v e rs u s th e r e c i p r o ­ c a l o f th e a b s o lu te te m p e ra tu re i s shown i n F ig u re 2 0 . The s lo p e o f t h e l i n e B i s 161;3 and th e d ip o le moment c a l c u l a t e d from t h i s i s JX =“ 0 .5 1 D. C h lo r o tr i f l u o r o e t h y le n e D a ta . The d i e l e c t r i c c o n s ta n t d a ta a re g iv e n i n T a b le XXVI, and th e c a l c u l a t i o n s a re sum m arized i n T ab le XXVII. D ip o le m om ent. The p l o t o f m o lar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f th e a b s o lu te te m p e ra tu re i s shown i n F ig u re 2 1 . The s lo p e o f th e l i n e B i s 9 0 k , and th e d ip o le moment c a lc u l a t e d from t h i s i s JJL - 0 .3 8 D. 9k TABLE XXEV DIELECTRIC CONSTANT DATA FOR PERFLUOROETHYL ETHER C(CaF6 )aP ) P re ssu re mm. o f Hg C a p a c ita n c e y>y. f M easurem ents a t 26.0°C 7 8 7 .5 7 2 1 .2 6 3 9 .9 5l*o.o 1*26.5 3 0 8 .3 19 9.1* 9 6 .0 0 .5 1 .0 2 1 1.11*9 1 .3 0 3 1.1*97 1.711* 1.932 2 .1 2 6 2 ,3 U 2.1*86 P re s s u r e mm„ o f Hg C a p a c ita n c e y-y-t M easurem ents a t 1*7 .0°C 7 8 7 .9 6 96.2 598.2 5 0 5 .2 3 9 9 .3 3 0 3 .3 1 9 7 .0 1 0 3 .7 0 .2 1 .2 2 2 1 .3 8 0 1.561* 1.727 1 .9 0 9 2 .0 7 1 2.21*8 2.1*09 2.581 M easurem ents a t 3l*.8 C M easurem ents a t 55.o°c 7 9 1 .1 700.1* 5 9 6 .0 1*90.5 3 9 9 .0 291*. 6 1 9 2 .8 9 7 .8 0 .2 787 .3 688.1 598.2 1*97.7 397.1* 295.2 1 93.7 9 9 .5 0 .3 1 .U 3 1 .282 1.1*79 1 .6 7 7 1.81*1 2 .0 2 7 2 .2 0 3 2 .3 7 3 2.51*1 Me a su rem e n ts a t 1*0.9°C 791*. 6 7 0 3 .9 5 9 7 .5 1*9 0 .6 1*00.0 2 9 6 .8 2 0 0 .0 9 8 .8 0 .1 0 .8 7 8 1.037 1 .2 2 6 1.1*20 1.581* 1 .7 6 3 1 .9 3 0 2.102 2 .2 6 3 1 .3 6 0 1 .5 3 5 1 .6 9 1 1 .8 5 9 2.028 2 . 191* 2 .3 5 9 2.517 2.683 M easurem ents a t 62.3°C 7 9 6 .1 70 2 .9 5 9 8 .9 5 0 0 .1* 3 9 9 .1 2 9 8 .1 1 9 7 .3 99.1* 0 .2 1.1*25 1 .5 8 5 1 .7 6 0 1 .9 2 3 2 .0 8 6 2.252 2.1*15 2 .5 7 6 2 .7 3 8 95 TABLE m v P ressu re mm. o f Hg M e a s u r e m e n ts 79k.h 6 9 9 .0 5 9 6 .9 5 0 2 .7 3 9 8 .1 2 9 7 .8 1 9 7 .0 10U .3 0 .1 M e a s u r e m e n ts 7 8 2 .9 695.1* 5 9 9 .9 505.1* 3 9 9 .1 296.1* 1 9 9 .0 1 1 2 .0 0 .2 C a p a c ita n c e a t 72.7°C 1.1*27 1 .5 8 5 1.71*7 1 .8 9 2 2.057 2.212 2 .3 6 8 2 . 5H* 2 .6 8 6 a t 82.2°C 0.1*51 0 .6 0 0 0 . 71*6 0 .8 9 5 1 .052 1 .2 0 6 1 .3 5 5 1.501* 1 .6 6 2 (CONTINUED) P ressu re mm. o f Hg M e a s u r e m e n ts 787.1* 696.0 5 9 9 .6 1*99.1* 3 9 7 .9 2 9 5 .8 1 9 9 .8 9 9 .0 0 .3 M e a s u r e m e n ts 7 8 3 .0 6 9 3 .9 5 9 7 .1 501.7 3 9 6 .2 28 8 .5 19l*.0 9 9 .8 0 .3 C a p a c ita n c e a t 91.8°C 0 .9 2 0 1 .0 5 8 1 .1 9 9 1.31*9 1 .5 0 2 1 .6 5 5 1 .7 9 3 1.9l*o 2.080 a t 1 0 0 .6°C 0 .9 8 9 1.122 1 .2 6 7 1.1*01* 1.562 1 .7 1 5 1 .8 5 2 1 .9 8 3 2 .1 2 3 96 TABLE XXV MOLAR POLARIZATION CALCULATIONS FOR PERFLUOROTHYL ETHER . A C JU/U f T em perature K 2 9 9 .3 3 0 7 .9 31U.0 3 2 0 .1 3 2 8 .1 3 3 5 .lt 3U 5.8 3 5 5 .3 3 6 lt.9 37 3 .7 1.U13 1.37U 1.3U 5 1 .2 9 1 1 .2 6 6 1 .2ii2 1 .1 9 1 1 .1 5 9 1 .1 2 3 1 .0 9 7 (e - l ) x 106 VM co/m ole PM co/m ole 1 x 103 T°K ItOOlt 3893 3811 3658 3587 3519 3375 328U 3182 3108 2lt ,556 25,279 25,779 26,280 26,973 2 7 ,5 3 6 28,390 2 9 ,1 7 0 29,958 30,681 32.7 3 2 .8 32 .7 32.0 32.2 3 2 .2 3 1 .9 3 1 .9 3 1 .7 3 1 .7 3.3U3 3.2U8 3.18U 3.12lt 3.0li8 2.9 8 1 2 .892 2 .8 llt 2.7UO 2 .6 7 6 * R e p la c e a b le c a p a c ita n c e C0 = 353 M M ? * 3k 32 30 2.6 2.8 3 .0 3.2 3.U F ig u r e 2 0 . Molar p o la r iz a t io n v e r su s th e r e c ip r o c a l o f th e a b s o lu te tem p eratu re f o r p e r f lu o r o e t h y l e t h e r . 97 TABLE XXVT DIELECTRIC CONSTANT DATA FOR CHLOROTRIFLUOROETHILENE (C C IF«C F2 ) P re ssu re mm. o f Hg C a p a c ita n c e MM* P re s s u r e mm. o f Hg C a p a c ita n c e MM* Me asurem e n t s a t 28.2°C Me a s u r erne n t s a t 51*.1*°C 7 8 1 .3 7 0 1 .2 6 0 1 .0 1*98.5 1*06.8 3 0 3 .9 200.1* 9 5 .0 0 .5 7 88.2 705.8 5 9 9 .1 1*9 5 .0 1*07.7 2 9 7 .0 1 8 7 .9 1 0 7 .3 0 .8 1.522 1 .6 3 2 1 .7 5 9 1 .8 9 3 2 .0 2 5 2 .1 5 0 2.281* 2.1*21 2.51*5 Me ss u r erne n't 3 a t 3l*.7°C 7 8 3 .5 7 0 0 .0 581*.3 1*91*. 9 1*01.2 2 9 6 .8 2 0 5 .9 1 0 7 .3 0 .8 1.861* 1.9 7 3 2 .1 2 0 2.231* 2 .3 5 9 2.1*98 2 .6 1 9 2.71*7 2 .8 8 1 M easurem ents a t 1*1* .5°C 78JU .3 688.0 605. 6 U93.7 393*3 291*. 6 19U.0 1 0 0 .0 0 .5 1.307 1.1*32 1.537 1.677 I . 8O3 1.923 2.01*8 2 .166 2.287 1 .0 9 3 1 .1 9 2 1 .3 1 9 1.1*1*1* 1 .5 5 1 1 .6 8 7 1 .8 0 9 1 .9 0 6 2 .0 3 0 M easurem ents a t 6 3 .6 C 7 7 6 .8 701*. 3 581*. 7 1*86.0 3 93.7 3 0 2 . 1* 1 9 1 .1 9 9 .0 0 .1 1 .2 3 7 1 .3 1 8 1.1*62 1.577 1.685 1 .7 8 8 1 .9 1 3 2.020 2.127 M easurem ents a t 7 6 .5 C 779.8 695.7 597.1* l*9l*.l 399.2 297.5 1 9 5 .5 101.1* 0 .2 1 .5 5 5 1 .6 5 1 1.7 5 9 1.873 1 .9 8 0 2 .088 2.200 2.305 2 .Lie 98 TABLE XXVI (CONTINUED) P ressu re irnn. o f Hg C a p a c ita n c e jjijjL f M e a s u r e m e n ts a t 8 ii.2 ° C 7 8 3 .2 7 0 3 .8 608.8 5 0 0 .0 3 8 3 .1 2 8 7 .0 2 0 8 .5 1X7.3 0 .8 1.5 6 9 1 .6 5 9 1 .7 5 8 1.877 2 .0 0 3 2 .1 0 5 2 .1 9 0 2.293 2.1(22 M easurem ents a t 92 .6°C 7 8 1 .6 692.2 5 8 9 .6 5 0 3 .1 3 9 2 .1 2U2.5 1 3 5 .9 0 .5 2 .0 0 3 2 .0 9 6 2 .2 0 0 2 .2 9 6 2.1(16 2 .5 7 6 2 .6 8 9 2.837 M e a s u r e m e n ts a t 101+.2®C 7 7 7 .3 6 9 9 .5 5 9 6 .5 500.7 3 9 0 .5 29U.8 1 9 0 .8 1 0 1 .6 0 .5 0 .6 5 5 0.733 0.81(1 0 .9 3 6 1.01(7 l.U d i 1.21(8 1.3U0 1.1(1(8 99 TABLE X X V II MOLAR POLARIZATION CALCULATIONS FOR CHLOROTRIFLUOROETHYLENE T em p era tu re °K A c* MM f 0 .9 9 2 0 .9 8 6 0 .9 5 1 0 .9 1 2 0 .9 0 7 0.81*1 0 .8 2 3 0 .8 1 3 0 .7 7 8 3 0 1 .3 3 0 7 .8 3 1 7 .6 3 2 7 .3 3 3 6 .7 31*9.6 3 5 7 .3 3 6 5 .7 3 7 7 .3 (e - l ) x 10® VM cc/m o le PM cc/m o le 2729 2712 2616 2508 21*95 2311* 2261* 2367 211*0 2ii,737 25 ,2 7 0 2 6 ,0 7 5 26,888 27,6U3 28,702 2 9 ,3 ^ 1 3 0 ,021* 3 0 ,9 7 6 22 .5 2 2 .8 22.7 2 2 .5 2 2 .9 22 .1 2 2 .1 2 2 .3 2 2 .0 i , x 103 T&k 3 .3 1 9 3.21*9 3.H*9 3 .0 5 3 2 .9 7 0 2 .8 6 0 2.7 9 7 2.731* 2 .6 5 0 ■* R e p la c e a b le C a p a c ita n c e C0 ® 3&3 M M f. 2k 22 20 2.6 2.8 3 .0 *0* T K 3 .2 103 F ig u r e 21* M olar p o l a r i z a t i o n v e rs u s th e r e c i p r o c a l o f t h e a b s o lu te te m p e ra tu re f o r c h l o r o t r i f l u o r o e t h y l e n e . 100 D is c u s s io n o f E r ro r s The l a r g e s t f a c t o r g o v e r n in g t h e a c c u r a c y o f t h e d i e l e c t r i c con­ s t a n t m e a su r e m e n ts w as t h e ”d r i f t ” o f th e b ea t freq u en cy . in p a r t to th e i n s t a b i l i t y o f t h e o s c i l l a t o r s , b u t w as m o s t l y d u e t o s m a ll v ib r a t io n s i n W hen t h e s t i r r e r s n e g lig ib le . d e lic a te th e d i e le c t r i c w ere n o t in c e lls T h i s w as d u e cau sed by th e b a th s t ir r e r s . o p e r a t io n t h e d r i f t w as o b s e r v e d t o b e T h e d r i f t w as m ore p r o n o u n ce d i n C e l l I , b eca u se o f i t s c o n s t r u c t i o n , t h a n i n C e l l I I w h ic h w as m o r e r i g i d l y b u i l t . I t w as th e r e fo r e n ecessa ry to ca r ry o u t se p a r a te e r r o r a n a ly s e s , one f o r t h e f l u o r o c a r b o n d e r i v a t i v e s f o r w h ic h C e l l I w a s u s e d , an d o n e fo r C e ll I I and t h e h a lo g e n f l u o r i d e s . H a lo g e n F l u o r i d e s The s e n s i t i v i t y o f t h e c a p a c i t a n c e m e a s u r e m e n ts h a d a s an u p p e r lim it th e s m a lle s t c a p a c ita n c e p r e c is io n con d en ser. b e a t-fr e q u e n c y d r if t of 0.0005 M b ? > s o s lig h tly le s s th a n i n c r e m e n t w h ic h c o u l d b e r e a d o n t h e d u r in g th e p e r io d o f s e v e r a l th a t th e t o t a l u n c e r ta in ty in - 0 .0 0 1 > t y u f . d e c r e a s in g a s y m p to tic a lly to ju i^ tf. A p lo t sh o w n i n F i g u r e 2 2 . The r u n s w as o f t h e o r d e r e a c h r e a d i n g w as T h us t h e t o t a l p r o b a b le e r r o r i n t h e c a p a c i t a n c e m e a s u r e m e n t s w as 1 0 0 # f o r i n c r e m e n t s o f 0 .1 0 0 . T h i s i n c r e m e n t w as e q u a l t o 0 . 0 0 0 3 ^ C = 0 .0 0 1 a b o u t one p e r c e n t f o r v a lu e s e q u a l to o f th e p r o b a b le e r r o r v e r s u s ^ C fo r C e ll I I is 9 101 Percent E rror 100 20 0 0 .0 2 5 0.050 A C C a p a c ita n c e in c re m e n t, F ig u re 2 2 . in c r e m e n t, ja| a f P ro b a b le e r r o r a s a f u n c tio n o f c a p a c ita n c e AC f o r a s i n g l e o b s e r v a tio n u s in g C e l l I I . Percent Error 80 60 ho 20 O O 0.100 0.200 0.300 Z i C , C a p a c ita n c e in c re m e n t, juji f F ig u re 2 3 . P ro b a b le e r r o r as a f u n c tio n o f c a p a c ita n c e in c re m e n t, ^ C f o r a s i n g l e o b s e r v a tio n u s in g C e ll I . 102 C e ll c a l ib r a t io n . The maximum p ro b a b le e r r o r i n th e c a l i b r a t i o n o f th e d i e l e c t r i c c e l l was d e te rm in e d by d i f f e r e n t i a t i o n o f E q u atio n 21 which g iv e s AC A c 0 where AC0, te r m s . - A C) -------------- — A (C ( e - i) A ( € - l ) , and -1) + ( 23) ( e - 1) A ( A C) r e p r e s e n t th e e r r o r s i n th e s e As i n d i c a t e d i n T a b le IX , th e a v erag e c a p a c ita n c e in cre m e n t d u r in g a r u n was e q u a l to O.Oll^ >*■>*f . T h is c o rre sp o n d s to a p ro b a b le e r r o r o f se v en p e r c e n t as shown i n F ig u re 2 2 . The v a lu e f o r A C was ta k e n a s th e t o t a l c a p a c ita n c e change d u rin g a r u n , 0 .1 2 3 and se v e n p e r c e n t o f t h i s o r 0 .0 0 9 was th e v a lu e o f (T ab le X) , A t AC) . The mean v a lu e f o r th e d i e l e c t r i c c o n s ta n t o f c arb o n d io x id e r e p o r te d by M a ry o tt and B uckley (5 2 ) i s ( € A ( € - 1) - l ) x 106 = 922 - 1 , hence - 1 x 10”6 . The e r r o r s i n th e p r e s s u r e m easurem ents were n e g l i g i b l e s in c e th e e r r o r i n each p r e s s u r e r e a d in g was - 0 .0 5 mm. o f m ercury which c o rre sp o n d e d to ! l l 10"6 S u b s titu tin g of s ix p e rc e n t in 1. th e above v a lu e i n E q u a tio n 23 th e r e p la c e a b le c a p a c ita n c e CQ o f C e ll C0 - D i e l e c t r i c c o n s ta n t m e a su re m e n ts. and a g a in d i f f e r e n t i a t i n g g iv e s 133 i g iv e s an u n c e r t a i n t y I I , or 9 K M f. S o lv in g E q u atio n 21 f o r ( € - l) 103 A ( C - 1) AC — co - A (A C ) --------C0 A C0 w here th e te rm s a re th e same a s i n E q u a tio n 2 3 . ( 21*) The d a ta f o r c h lo r in e t r i f l u o r i d e show th e a v e ra g e c a p a c ita n c e in c re m e n t d u rin g a ru n to be , c o rre s p o n d in g t o an e r r o r o f th r e e p e r c e n t , o r Ac) 1 0 .0 0 9 yi'M’f s in c e th e av erag e v a lu e o f th e c a p a c ita n c e change f o r an 0 .0 3 0 atm osphere o f th e gas was 0 .3 0 0 f . The e r r o r s i n th e p r e s s u r e + m easurem ents were s l i g h t l y l a r g e r h e r e , H e lic o id gage was u s e d . = 1 raw. o f m e rc u ry , s in c e th e However t h i s c o rre sp o n d e d to o n ly 0 ,0 0 0 3 and i s a g a in n e g l i g i b l e . These v a l u e s , s u b s t i t u t e d i n E q u a tio n ( 2h) g iv e a n a v erag e e r r o r i n th e d i e l e c t r i c c o n s ta n t m easurem ents o f c h lo r in e t r i f l u o r i d e o f £ . ( e- - 1) - - 200 X 10~# o r e ig h t p e r c e n t . M olar p o l a r i s a t i o n . apm where - rV H }* - D i f f e r e n t i a t i o n o f E q u a tio n 12 g iv e s v a ( * + 2)) - l }) i s th e e r r o r i n t h e m o lar volume c a l c u l a t i o n , and th e o th e r te rm s a re th e same as i n th e above e q u a tio n s . The e r r o r i n th e m o la r volume was assum ed to be no more th a n 0.1/6 f o r c h lo r i n e t r i f l u o r i d e , s i n c e th e B e r t h e l o t e q u a t i o n - o f - s t a t e was u s e d . F o r a l l o th e r m o lar volume c a l c u l a t i o n s th e i d e a l gas law was used and th e e r r o r assumed to be no more th a n one p e r c e n t . % T h is was j u s t i f i a b l e s in c e i n m ost c a se s 102* p r e s s u r e s were l e s s th a n 200 imn. o f m e rc u ry . S u b s t i t u t i n g in th e above e q u a tio n an a v e ra g e v a lu e o f VM ( 3 0 ,0 0 0 c c ./W > le ), and & (€ - l) (200 x 10 (30 cc ./m o le) , ) , th e av erag e e r r o r i n th e m o lar p o l a r i s a t i o n o f c h lo r in e t r i f l u o r i d e was found t o be 1 0.1* c c ./m o le . D ip o le m om ent. The e r r o r s i n th o s e d ip o le moments wliich were d e te rm in e d from th e s lo p e s o f th e p l o t s o f Pj^ v e rs u s l/T were found by d i f f e n t i a t i o n o f th e e q u a tio n /P » - P U -0.0128 / M M v i/r* - l/r w here th e term u n d e r t h e s q u a r e - r o o t s ig n i s th e slo p e i n E q u a tio n 1 5 . D i f f e r e n t i a t i o n o f t h i s e q u a tio n g iv e s ( P ' - P M) a /A T * _ J * — * - 3 ( ----- 1 T, a AT \ - --------- ) + TaJ &P* + A P m — * -----------*L (d A * I - lA J tt* * - PM) ) a J where th e v a lu e s o f P* a t T 1 and PM a t T were fo und from th e p l o t s o f M M Pjj v e rs u s l / T . These v a lu e s were ta k e n a t th e low er and u p p e r ends o f th e te m p e ra tu re r a n g e , r e s p e c t i v e l y . m easurem ents A T 1 and S ince e r r o r s i n th e te m p e ra tu re + o a re e q u a l t o - 0.05> C , th e f i r s t terra in th e e q u a tio n i s n e g l i g i b l e and th e l a s t term i n th e e q u a tio n i s th e c o n tr i b u t ­ in g f a c t o r i n th e e r r o r . The l a s t term i n d ic a t e s t h a t th e p e rc e n ta g e e r r o r w i l l be much g r e a t e r when th e d ip o le moment i s s m a ll, o r (P^ - PM> i s s m a ll, and when th e te m p e ra tu re ra n g e i s s m a ll. S u b s t i t u t i o n o f th e a p p r o p r ia te terras i n t h i s e q u a tio n shows t h a t th e e r r o r i n th e d ip o le moment o f c h lo r in e t r i f l u o r i d e i s - 0 .1 1 D. 105 The e r r o r i n th o s e d ip o le moments c a l c u l a t e d u s in g m o lar r e f r a c ­ t i o n d a ta was found by d i f f e r e n t i a t i o n o f E q u a tio n 1 7 , which g iv e s Ay - * 0.006k (PM - R) A. T + ( A P + 6R ) T M_______________j*___________ (PM - R) T where & R i s th e e r r o r i n th e m o la r r e f r a c t i o n . fo r ^ R The v a lu e s u b s t i t u t e d in c lu d e d an e s tim a te o f th e d is c re p a n c y betw een m o la r r e f r a c t i o n , w hich d ep ends o n ly on th e e l e c t r o n i c p o l a r i s a t i o n , and m o lar in d u ced p o l a r i s a t i o n , which i s th e sum o f t h e e l e c t r o n i c p o l a r i s a t i o n p lu s th e atom ic p o l a r i s a t i o n . I n many c a s e s , e s p e c i a l l y w ith th e f l u o r i d e s , e x p e rim e n ta l v a lu e s o f R and d i f f e r by a s much as tw en ty p e r c e n t. T h is n e v e r t h e l e s s c a u s e s v e ry l i t t l e e r r o r i n th e d ip o le moment o f a compound w ith a r e l a t i v e l y la r g e moment, as in d ic a t e d by c a l c u l a t i o n s made on io d in e p e n t a f l u o r i d e . Assuming th e e r r o r i n th e m o la r r e f r a c t i o n to be t h a t r e p o r t e d by M alik (55) (R « 1 9 .2 1 0 .3 c c ./ in o l e ) , th e e r r o r c a l c u l a t e d u s in g th e above e q u a tio n was found t© be 1 0 .0 7 D. Assuming th e d is c r e p a n c y betw een th e m o lar r e f r a c t i o n and th e m olar in d u ced p o l a r i s a t i o n t© be as much a s 25$ gave an e r r o r o f o n ly ^ 0 .0 9 0 . F lu o r ©carbon D e r iv a tiv e s The e r r o r s i n th e d ip o le moment d e te rm in a tio n s o f th e flu o ro c a rb o n d e r i v a t i v e s w ere c a l c u l a t e d by th e sa n e m ethod a s was u se d f o r th e h a lo g e n f l u o r i d e s . The maximum p ro b a b le e r r o r f o r a s i n g l e c a p a c ita n c e m easurem ent u s in g C e l l I i s p l o t t e d v e rsu s A C i n F ig u re 2 3 . i n th e r e p l a c e a b l e c a p a c ita n c e o f C e ll I was found t o be 1 h The e r r o r f . 106 A lth o u g h th e e r r o r s f o r sm a ll c a p a c ita n c e m easurem ents were l a r g e r f o r C e l l I th a n C e l l X I, th e l a r g e r r e p la c e a b le c a p a c ita n c e o f C e ll I more th a n com pensated f o r t h i s . The e r r o r s c a l c u l a t e d were i n e v e ry c a se th e maximum p ro b a b le e rro rs. The p r e c i s i o n o f th e m easurem ents was much g r e a te r th a n t h i s and i n d ic a t e d t h a t th e a c t u a l e r r o r s w ere p ro b a b ly l e s s th a n th o s e c a lc u la te d , h o w ev er, s in c e th e r e was a p o s s i b i l i t y t h a t a d s o r p tio n o f g a se s on th e p l a t e s o f t h e d i e l e c t r i c c e l l s in tro d u c e d e r r o r s which were i n d e t e r m i n a t e , and b e c a u se th e e r r o r s due t o th e d e v ia tio n s from i d e a l i t y o f t h e g a se s were unknown, a l l th e d ip o le moments a re r e p o r te d w ith th e e r r o r s c a l c u l a t e d f o r th e u p p e r l i m i t o f u n c e r t a i n t y . The d ip o le moments o f th e compounds s tu d ie d i n t h i s i n v e s t i g a t i o n , and t h e i r maximum p ro b a b le e r r o r s , a re p r e s e n te d i n T a b le XXVIII. The v a lu e s o f th e In d u ced m o la r p o l a r i z a t i o n , c a l c u l a t e d by means o f a l e a s t - s q u a r e s tr e a tm e n t o f th e PM v e rs u s l / T d a ta , a re a ls o g iv e n f o r th o s e compounds f o r w hich th e s e d a ta were o b ta in e d , and compared w ith th e m o la r r e f r a c t i o n s found by M alik (5>5) . 107 TABLE X X V III DIPOLE MOMENTS AND MOLAR INDUCED POLARIZATIONS DETERMINED IN THIS INVESTIGATION D ip o le Moment, D Maximum P ro b a b le E rro r, D M olar Induced P o l a r i* a ti o n M olar* R e f r a c tio n BrF^ l.iiO - O .lU 2 1 .8 cc ./m o le 15 .U8 c c ./ n o l e C1F3 0 ,7U 0 .1 1 1 3 .6 1 0 . 3h 2 .2U 0 .0 9 — — BrFa 1 .3 3 O.U4 — — n-C 3F 7H 1 .6 2 0 .1 0 1 3 .0 1 6 .6 7 c y c lic - ( C F 3) 40 0 .5 6 0 .1 2 2 6 .5 — 0 .5 1 0 .1 2 2 7 .2 23 .1*9 0 .3 8 0 .1 0 2 0 .2 15.77 Compound CC1F«CF2 « R e fe re n c e (5£) 108 V I. DISCUSSION OF RESULTS H alogen F lu o r id e s C h lo r in e t r i f l u o r i d e . The s t r u c t u r e o f c h lo r in e t r i f l u o r i d e has been a c c u ra g e ly d e te rm in e d from m ic ro w a v e -s p e c tra l d a ta (12) . T h is i s th e o n ly h a lo g e n f l u o r i d e , e x c e p t th e d ia to m ic compounds, f o r which bond d i s t a n c e s and bond a n g le s have b e e n a s s ig n e d . a lr e a d y b e e n p r e s e n te d i n T a b le I . T h is s t r u c t u r e has W ith t h i s in fo rm a tio n and th e d ip o le moment o f c h lo r i n e m o n o flu o rid e , th e t h e o r e t i c a l v a lu e f o r th e d ip o le moment o f c h lo r in e t r i f l u o r i d e can be c a l c u l a t e d . The d ip o le moment o f c h lo r in e t r i f l u o r i d e s h o u ld be t h a t o f c h lo r in e m o n o flu o rid e p lu s th e s m a ll c o n tr i b u ti o n s from th e two C l-F bonds w hich a re a t an a n g le o f 87° 2 9 ' w ith th e c e n t e r C l-F bond* T hese c o n tr i b u ti o n s were c a l c u l a t e d t o b e -*O.Olj. f o r e ac h b o n d , r e s u l t i n g i n a v a lu e f o r th e t o t a l d ip o le moment o f 0*96 D, w hich i s somewhat h ig h e r th a n th e ob­ s e rv e d v a l u e . H ow ever, th e bond c o n tr i b u ti n g th e m ost t o th e t o t a l moment i s s h o r t e r by 0*03 2 th a n t h a t i n c h lo r in e m o n o flu o rid e which c o u ld a c c o u n t f o r t h e d i f f e r e n c e s in c e th e s h o r t e r bond sh o u ld be a s s o c i ­ a te d w ith g r e a t e r c o v a le n t c h a r a c t e r and lo w e r moment. Brom ine t r i f l u o r i d e . The s t r u c t u r e o f brom ine t r i f l u o r i d e i s p ro b a b ly p l a n a r w ith a s t r u c t u r e s i m i l a r t o t h a t o f c h lo r in e t r i f l u o r i d e , a lth o u g h th e bond d is ta n c e s and a n g le s have n o t b een a c c u r a te ly d e te rm in e d . I t was assum ed t h a t th e bond a n g le s i n brom ine t r i f l u o r i d e were th e same 109 aa th o s e i n c h lo r in e t r i f l u o r i d e , and t h a t th e bond moment o f th e B r-F bonds was e q u a l t o th e d ip o le moment o f brom ine m o n o flu o rid e * These a ssu m p tio n s gave a c a l c u l a t e d v a lu e f o r th e d ip o le moment o f 1.1*0 D w hich a g re e s w ith th e e x p e rim e n ta l v a lu e o f 1 .3 3 - O.ll* w ith in th e e x p e rim e n ta l e r r o r . Bromine p e n t a f l u o r i d e . S e v e ra l s t r u c t u r e s f o r brom ine p e n ta f lu o r id e a re p o s s i b l e , i n c lu d in g a t r i g o n a l b ip y ra m id , a t e t r a g o n a l pyram id w ith th e brom ine atom above th e p la n e o f th e b a s e , and a p la n a r p e n ta g o n . The r e l a t i v e l y l a r g e d ip o le moment o b se rv ed (1.1*0 D) e lim in a te s any o f th e above s t r u c t u r e s , a s th e y would e x h i b i t e i t h e r no d ip o le moment o r a v e ry s m a ll moment a t th e m o st. A r e g u l a r o c ta h e d ro n , w ith th e brom ine atcm i n th e p la n e o f th e fo u r f l u o r i n e atoms and an u n sh a re d e le c t r o n p a i r o c cu p y in g th e s i x t h c o rn e r sh o u ld have a d ip o le moment e s s e n t i a l l y e q u a l t o t h a t o f brom ine m o n o flu o rid e (1 .2 9 D) , s in c e th e fo u r B r-F bonds i n a p la n e would n o t c o n tr i b u te t o th e t o t a l d ip o le moment. If th e brom ine atom i s s l i g h t l y above th e p la n e o f th e f o u r f l u o r i n e atoms so t h a t th e f o u r F -B r-F a n g le s have th e same v a lu e as th e F -C l-F a n g le s D is to r te d o c ta h e d ro n R e g u la r o c ta h e d ro n F i n c h lo r i n e t r i f l u o r i d e , th e n a l a r g e r d ip o le moment f o r brom ine p e n ta f l u o r i d e would be e x p e c te d . A s t r u c t u r e o f t h i s ty p e would i n d ic a t e t h a t 110 two f lu o r i n e atoms add s y m m e tr ic a lly ab ou t th e bromine atom o f brom ine t r i f l u o r i d e t o form brom ine p e n t a f lu o r i d e . The c a lc u la t e d v a lu e f o r th e d ip o le moment f o r t h i s s t r u c t u r e i s 1 .5 2 D which a g rees w ith th e e x p e r im e n ta l v a lu e o f l.U O 1 O .ll* D about a s w e ll as does th e v a lu e c a l c u l a t e d f o r th e r e g u la r o c ta h e d r a l s tr u c t u r e (1 .2 9 D) . Some su p p ort f o r th e d i s t o r t e d s tr u c t u r e i s found i n th e dipol© moment d ata f o r io d in e p e n t a f l u o r i d e . I o d in e p e n t a f l u o r i d e . The la r g e v a lu e f o r th e d ip o le moment o f io d in e p e n t a f lu o r id e c a n b e s t be e x p la in e d by a s tr u c tu r e s im ila r t o th e d i s ­ t o r t e d o c ta h e d r a l arrangem ent s u g g e ste d f o r bromine p e n t a f l u o r id e . A ssum ing th e d ip o le moment o f th e I -F bond to be e q u a l t o th e e l e c t r o ­ n e g a t i v i t y d i f f e r e n c e ( 1 . 5 ) , s in c e th e e l e c t r i c moment o f io d in e mono­ f l u o r i d e i s unknown, and assum ing a s t r u c t u r e s im ila r t o th e d is t o r t e d o cta h ed ro n shown above f o r brom ine p e n t a f lu o r id e , th e d ip o le moment i s c a l c u l a t e d t o be 1 ,9 D . T h is i s c o n s id e r a b ly low er th an th e e x p e r i­ m e n ta l v a lu e o f 2 , 2 b - 0 .0 9 D . However, an o c ta h e d r a l s tr u c tu r e in which th e io d in e l i e s i n th e p la n e o f th e fo u r f lu o r in e s would g iv e an ev en lo w e r c a l c u l a t e d moment o f 1 .5 D . S in c e th e bond moments o b ta in e d from e l e c t r o n e g a t i v i t y d i f f e r e n c e s o c c a s io n a lly d i f f e r from th e observed bond moments b y a s much as 0 . 3 to 0.14 D, th e d isc r e p a n c y may be o n ly a p p a r e n t. The h ig h v a lu e o f th e ob served moment co u ld a ls o be due in p a r t t o th e io d in e and f lu o r i n e e x h ib it in g unu su al e l e c t r o n e g a t i v i t i e s i n a compound o f t h i s t y p e , where a la r g e number o f liig h ly e l e c t r o ­ n e g a t iv e groups surround a h ig h ly e l e c t r o p o s i t i v e c e n t r a l atom; how ever, i n t h i s c a s e one would e x p e c t a s m a lle r r a th e r th a n a la r g e r moment. I ll F r e q u e n tly p ro p o se d sy m m e tric a l s t r u c t u r e s , such as th e t r i g o n a l b ip y ra m id and th e t e t r a g o n a l p y ra m id , a re d e f i n i t e l y e x clu d ed by th e h ig h d ip o le moments o b se rv ed f o r b o th io d in e p e n ta f lu o r id e and brom ine p e n ta flu o rid e . F lu o ro c a rb o n D e r iv a tiv e s 1 ,1 ,1 .2 .2 , 3 .3 ^ H e p ta flu o ro p ro p a n e . F The d ip o le moment o f t h i s compound F F . - 1C -1 C *- C - H F I F I F I F w ould be e x p e c te d to be th e same as t h a t o f t r if lu o r o m e th a n e , a s was fo u n d t o be t h e c a s e . The moment o f tr if lu o r o m e th a n e i s 1.61*5 D (T a b le XV) and th e o b se rv e d moment o f 1 , 1 , 1 , 2 , 2 ,3 ,3 -h e p ta flu o ro p ro p a n e i s 1 .6 0 - 0 .1 0 D. H ow ever, b o th o f th e s e compounds would be e x p e c te d t o have d ip o le moments h ig h e r th a n th o s e o b s e rv e d . The c o m p le te ly f l u o r i n a t e d compounds have a ero moments, so th e s u b s t i t u t i o n o f a hydro g en f o r a f l u o r i n e atom sh o u ld p roduce a moment e q u a l t o th e sum o f a C - F dipol© and a C-H d ip o le s in c e th e y a re o p p o s ite ly d i r e c t e d . The C-F bond moment i s l . l i D and th e C-H bond moment i s 0,1* D (5 6 ) hence th e moment o f a f lu o ro c a rb o n w ith a s in g le C-H bond sh o u ld be a p p ro x im a te ly 1 .8 D. However, j u s t as th e moments o f m e th y l- and e t h y l f l u o r i d e a re h ig h e r th a n p r e d ic te d b eca u se o f in d u c tiv e e f f e c t s , th e moments o f 1 , 1 , 1 , 2 , £ , 3 ,3 -h e p ta flu o ro p ro p a n e and tr if lu o r o m e th a n e a re lo w er due to th e in d u ce d p o s i t i v e c h a r a c te r o f th e 112 c arb o n atom i n th e C-H b o n d , which re d u c e s th e m agnitude o f th e C-H d ip o le . T h is e f f e c t te n d s to lo w er th e o v e r - a l l moment o f th e s e com pounds. P e r f lu o r o te tr a m e th y le n e o x id e and p e r f l u o r o e t h y l e t h e r . F-C----------C-F F-C-F F-C-F F- F- T hese two ,9 “ F 0 compounds s h o u ld have e s s e n t i a l l y th e same d ip o le moment s in c e th e c o n t r i b u t i n g d ip o le s l i e m a in ly a lo n g th e two C-O axes a t th e same a n g le , a b o u t 1 0 8 ° , i n e ach compound. The v a lu e o f th e d ip o le moment f o r 1 , 1 , 1 ,2 ,2 ,3 ,3 -h e p ta flu o ro p ro p a n e i n d i c a t e s t h a t th e group moment o f th e p e r f lu o r o p r o p y l group i s th e same a s th e moment o f a p e r f lu o r o m e th y l g ro u p . ' T h e re fo re i t i s assum ed t h a t th e p e r f l u o r o e t h y l group h a s th e same moment, and i s e q u a l t o th e moment o f th e C-H bond su b ­ t r a c t e d from th e moment o f l , l , l , 2 , 2 , 3 , 3- h e p ta f lu o r o p r o p 0n e , o r 1 .3 D. The C-O bond moment ( 0 .8 D) i s o p p o s ite ly d i r e c te d to t h a t o f th e p e r ­ f l u o r o e t h y l g ro u p , so t h a t th e d i f f e r e n c e betw een th e two g iv e s th e moment d i r e c t e d a lo n g t h e C-O a x is i n p e r f lu o r o te tr a m e th y le n e oxide and i n p e r f l u o r o e t h y l e t h e r , and i s e q u a l to 0 .5 D i n each c a s e . T h ere a re two o f th e s e moments a t an a n g le o f ab o u t 108° w hich r e s u l t s i n a t o t a l c a l c u l a t e d moment o f 0 .5 5 D lb** each o f th e two compounds. 113 T h is v a lu e i s i n good ag reem en t w ith th e o b se rv e d v a lu e s o f 0 .5 6 t 0 .1 2 D f o r p e r f lu o r o te tr a m e th y le n e o x id e and 0 .5 1 1 0 .1 2 f o r p e r f lu o r o ­ e t h y l e th e r * C h lo ro triflu o ro e th y le n e . The d ip o le moment o f t h i s compound would be F l F l I F I Cl c =c e x p e c te d t o be th e d i f f e r e n c e betw een a C-F bond moment ( l.U 0) and a C -C l bond moment ( 1 .5 0) , o r 0 .1 D . i s h ig h e r t h a n t h i s . The o b se rv ed v a lu e o f 0 .3 8 - 0 .1 D T h is may b e e x p la in e d by th e in c r e a s e i n th e p o s i t i v e c h a r a c t e r o f t h e carbon atom i n th e C -C l bond in d u ced by th e e l e c t r o n e g a t i v e f l u o r i n e atoms a tta c h e d to i t and th e a d ja c e n t carb o n ato m . The o b se rv e d e l e c t r i c moments o f tric h lo r o f lu o r o m e th a n e and c h lo r o t r if l u o r o m e t h a n e , w hich sh o u ld each be e q u a l t o th e d if f e r e n c e b etw een th e C-F and th e C -C l bond m om ents, a re 0.2i5 and 0 .3 9 0 re s p e c tiv e ly . n il V II. SUMMARY iS g u ip m e n t f o r m e a s u r in g ; t h e d i e l e c t r i c th e to c o n s t a n t s o f co m p o u n d s i n v a p o r p h a se o v e r a r a n g e o f te m p e r a tu r e s w as c o n s t r u c t e d , d e te r m in e t h e D ie le c tr ic c e lls and u s e d d i p o l e m o m e n ts o f e i g h t com p ou n d s c o n t a i n i n g f l u o r i n e . an d a u x i l i a r y e q u ip m e n t w e r e c o n s t r u c t e d b o t h f o r m e a su r e m e n ts o n h i g h - b o i l i n g c o r r o s i v e l i q u i d s a n d f o r m e a s u r e m e n ts o n o r d in a r y l o w - b o il i n g l i q u i d s . T he com pounds s t u d ie d a n d t h e v a l u e s o f t h e i r d i p o l e m o m e n ts , w e r e : b r o m in e p e n t a f l u o r i d e , 1 .U 0 I 0 .1 i± D j c h l o r i n e t r i f l u o r i d e , 0.71+ 1 O . U D; i o d i n e p e n t a f l u o r i d e , 2.21+ - 0 . 0 9 D; b r o m in e t r i f l u o r i d e , 1 . 3 3 - O .lU D; 1 , 1 , 1 , 2 , 2 , 3 , 3 “h e p t a flu o r o p r o p a n e , 1 .6 2 o x i d e , 0.f>6 * 0 . 1 2 £ 0 . 1 0 D; p e r f l u o r o t e t r a m e t h y l e n e Dj p e r f l u o r o e t h y l e t h e r , 0 . 5 1 flu o r o e th y le n e , 0 .3 8 t 0 . 1 2 D; and c h l o r o t r i - - 0 .1 0 D . T h e d i p o l e m om ent o f c h l o r i n e t r i f l u o r i d e w i t h t h a t p r e d i c t e d fr o m m om ent s u p p o r t s a. s i m i l a r its know n s t r u c t u r e . a g r e ed r e a s o n a b ly w e ll T he o b s e r v e d e l e c t r i c s t r u c t u r e f o r b r o m in e t r i f l u o r i d e . T he h i g h d i p o l e m o m e n ts o b s e r v e d f o r b r o m in e p e n t a f l u o r i d e a n d i o d i n e p e n t a flu o r id e sh o w t h a t t h e y c a n n o t h a v e s y m m e tr ic a l s t r u c t u r e s . The la r g e m o m en ts c a n b e a c c o u n t e d f o r o n t h e b a s i s o f e i t h e r a r e g u l a r o c t a h e d r a l str u c tu r e b e tte r or a d is to r te d o c ta h e d r a l s t r u c t u r e , a lth o u g h th e l a t t e r ag reem en t w ith th e d a ta f o r io d in e p e n t a f lu o r id e . g iv e s 115 D ip o le moments were c a l c u l a t e d f o r th e f lu o ro c a rb o n d e r i v a ti v e s from bond m om ents, and com pared w ith th e e x p e rim e n ta l v a lu e s . The c a l c u l a t e d v a lu e s a g re e d w ith th e o b se rv ed moments i f th e in d u c tiv e e f f e c t s o f th e s t r o n g C-F d ip o le s were c o n s id e re d . 111 LITERATURE CITED 1 . H . B . Thom pson, P h . D . D i s s e r t a t i o n , M ichigan S ta te C o lle g e , 1953. 2 . J . H. S im ons, E d ., " F lu o r in e C hem istry'*, Academic P r e s s , I n c . , New Y o rk , 1 9 5 0 . H. S . B ooth and J . T . P in k s to n , d r . , The H alogen F l u o r i d e s , Chap. k , T . J . B r i c e , F lu o ro c a rb o n s - T h e ir P r o p e r t ie s and W artime D evelopm ent, C hap. 1 3 . L . A. B ig e lo w , The A c tio n o f E le m e n tary F lu o r in e upon O rganic Compounds, C hap. 1 1 . G. GELockler, The T h e o r e ti c a l A sp e c ts o f F lu o r in e C h e m istry , Chap. 1 0 . 3 . E . B . M a x ted , "Modern Advances i n In o rg a n ic C h e m istry ", The C lare n d o n P r e s s , O x fo rd , 19U7. k . N. N. Greenwood, R e v s. P ure and A p p l. Chem. ( A u s tr a li a ) 1 , dij. (1 9 5 1 ). 5 . A. G. Sharp® , Q u a r t. R e v s ., k , 115 (1 9 5 0 ). 6 . C . H. Townes, P h y s. R e v ., 7 3 , 133k (19U8) . 7 . D. A . G i l b e r t , A . R o b e r ts , and P . A. G risw o ld , P h y s. R e v ., 7 6 . 1723 (1 9 ^ 9 ). d . D. F . S m ith , M. T id w e ll, and D. V. P . W illia m s , P h y s. R e v ., 7 7 , U20 (1 9 5 0 ). 9 . I . A. S h ek a, Z h u r. F i z . K him ., 2^3, dB5 (19U9) . 1 0 . G. F r o e h lic h and W. Y o s t, Chem. B e r . , d 6 , 118U (1 9 5 3 ). 1 1 . D. W. M agnuson, J . Chem. P h y s ., 2 0 . 229 (1 9 5 2 ). 1 2 . D. F . S m ith , The Microwave Spectrum and S tr u c tu r e s o f C h lo rin e T ^ i f l u o r i d e , C a rb id e and C arbon C hem ical C o ., New York (1 9 5 2 ): N uc. S c i . A b s t r a c t s , 7,* (1953) . 117 1 3 . M. T . R o g e rs , A. L . W a h rh a ftig , and V. Schom aker, p a p e r p re s e n te d b e f o r e th e D iv is io n o f P h y s ic a l and In o rg a n ic C hem istry o f th e A m erican C hem ical S o c i e t y , A t l a n t i c C i t y , w. J . , A p r i l , 1 9 l 7 . I k . L . A. B ig e lo w , Chem. R e v s ., 1*0, $1 ( 1 9 l l ) . 1 5 . C . H. T ow nes, F . R . M e r r i t t , and B . D. W rig h t, P h y s. R e v .. 7 3 , 1 3 3 U U 9 U 8 ). — 1 6 . A. E . B a n n in g , F . B . Downing, e t a l . , In d . Eng. Chem., 3 9 , 329 1191*7) . ~ 1 7 . K . N. H a sa e ld in e and A . G. S h a rp e , " F lu o rin e and I t s Compounds11, M ethuen and C o ., L ondon, 1951. 1 8 . J . w. S h o o le r y , R . G. Shulm an, W. F . Sheehan, V. Schom aker, and D. M. l o s t , J . Chem. P h y s ., 1 9 , 1361 U 9 5 D . 1 9 . C . P . Smyth and K. P . M cA lpine, J . Chem. P h y s ., 2 0 . C. h99 (1931) . P . S m yth, J . Am. Chem. S o c . , 6 ^ , 57 ( 1 9 l l ) . 2 1 . N. J . L eo n ard and L . E . S u tto n , J . Am. Chem. S o c ., 7 0 , 1561 (1 9 1 8 ). 2 2 . D . R . L id e , P h y s. R e v ., 87, 227 U 9 5 2 ) . 2 3 . C . P . Sm yth, J . Am. Chem. S o c ., 7 3 , 5115 (.1951) . 2 l . R . G. Shulm an, B. P . D a ile y , and C . H. Townes, P h y s. R e v ., 7 8 , 115 U 9 5 0 ) . 2 5 . R . M. F u o s s , J . Am. Chem. S o c ., 6 0 , 1633 (.1938) . 2 6 . M. T . R o g ers and J . D. R o b e r ts , J . Am. Chem. S o c ., 68, 81*3(1915) 2 7 . M. T . R o g e rs , J . Am. Chem. S o c ., 69, 1*57 (1 9 l7 ) . 28. P . D ebye, P h y s ik . Z . , 1 3 , 97 (1 9 1 2 ). 29. P. D ebye, " P o la r M o le c u le s11, Dover P u b l i c a t i o n s , New Y ork, 1929. 3 0 . P . S ilo w , P o g g . A n n ., 156 , 389 (.1875). 31. A. P . Carm an, P h y s. R e v ., 2 l , 3 9 6 (.1921). 3 2 . R . F u e r t h , 2 . P h y s ik , 2 2 , 98 (1 9 2 1 ). . 118 3 3 . C . P . Sm yth, ’" D ie le c tr ic C o n sta n t and M o le cu lar S t r u c tu r e ” C hem ical C a ta lo g C o ., New Y ork, 1931. 9 31*. J . Herweg, V e rh a n d l. d e u t . p h y s. Ges . , 2 1 , 572 (,1919) . 3 5 . J . W.W illia m s and A. W e is s b e rg e r, J . Am.Chem. S o c ., 5 0 , 2332 (1928) . *— ’ 36. J . W. W illia m s , J . Am. Chem. S o c ., 5 2 , 1831 ( 1 9 3 0 ). 3 7 . C . T . Z ahn, P h y s . R e v ., 21*, 1*00 (1921*). 3 8 . W. W. W atso n , P r o c . R oy. S o c ., (London) ll* 3 « 558(1931*). 3 9 . S . Golden and E . B. W ilso n , J . Chetn. P h y s ., 1 6 , 669 (19U6) . 1*0. G. E . Hyde and D . F . lio r n ig , J . Chem. P h y s ., 61*7 (1 9 5 2 ), 1*1. E . B . W ilson and A. J . W e lls , J . Chem. P h y s ., 1U, 578 (191*6) . 1*2. A. F r a a e r , ’"M olecular R ays” , C am bridge, 1931. 1*3. J . C h ie n , J . Chem. E d u c ., 2l*, l*9l* (191*7) . 1*1*. A m erican R ad io R e la y L e a g u e , HThe R ad io A m a te u r's Handbook, H a r tf o r d , C o n n ., 1951* 1*5. H. B . Thompson, p r i v a t e com m unication. 1*6. J . L . S p e i r s , u n ^ p u lish e d w ork. 1*7. d . A. C o n n e r, E l e c t r o n i c s , 2h, 250 (1 9 5 1 ). 1*8. R . G ilm o n t, A n a l. C hem ., 2 0 , l*7l* (19l*8) . 1*9. R . L . B u rw e ll, J r . , A. H. P e te r s o n , and G. B . Rathm ann, R ev. S c i . I n s t r . , 1 9 , 608 (19l*8) . 5 0 . J . L . S p e ir s and M. T . R o g e rs , u n p u b lis h e d w ork. 5 1 . v an I t t e r b e c k and de C l i p p e l e i r , P h y s ic a , 11*, 3l*9 (191*8). 5 2 . A. A . M a ry o tt and F . B u c k le y , T ab le o f D i e l e c t r i c C o n sta n ts and E l e c t r i c D ip o le Moments o f S u b stan ces i n th e Gaseous S t a t e , N a tio n a l B ureau o f S ta n d a rd s C i r c u l a r 5 3 7 9 U. S . Government P r i n t i n g O f f i c e , W ash in g to n , D. C. 119 5 3 . J . N. G r i s a r d , h . A. B e rn h a rd t, and G. D. O l i v e r , J . Am. Chem. S o c ., 2 1 , 5725 (1951) . 5 5 . A. G. W orthing and J . G e ff n e r , "T re a tm e n t o f E x p e rim e n ta l D ata” , J . W ile y and S o n s, New f o r k , N. X ., 1953. 5 5 . J . G. M a lik , P h . D. D i s s e r t a t i o n , M ichigan S ta te C o lle g e , 1955 5 6 . L . P a u l in g , "N a tu re o f th e C hem ical B ond", C o r n e ll U n iv e r s ity P r e s s , I t h a c a , N. X ., 1 9 5 8 .